diff --git a/crates/misaligned-core/src/sim.rs b/crates/misaligned-core/src/sim/mod.rs
similarity index 94%
rename from crates/misaligned-core/src/sim.rs
rename to crates/misaligned-core/src/sim/mod.rs
index 464d6c85..4e61aa8d 100644
--- a/crates/misaligned-core/src/sim.rs
+++ b/crates/misaligned-core/src/sim/mod.rs
@@ -51,6 +51,7 @@ use crate::research::Research;
 #[cfg(test)]
 use crate::research::Track;
 use crate::rng::Rng;
+#[cfg(test)]
 use crate::save::SaveState;
 use crate::schedule::Schedule;
 use crate::sinks::{SinkFireReadout, SinkLedger};
@@ -62,6 +63,7 @@ use crate::work_grid::{
 mod communications;
 mod economy;
 mod perception;
+mod persistence;
 mod reach_build;
 mod social_plot;
 mod work;
@@ -658,43 +660,6 @@ impl Sim {
             .collect()
     }
 
-    /// Rebuild transient caches after construction or save load. These values
-    /// are detection aids, not save state: persistent truth lives in the
-    /// people/reach/machine/intel fields.
-    pub fn rebuild_transient_state(&mut self) {
-        self.last_wired_moves.clear();
-        self.last_work_consumptions.clear();
-        self.last_work_productions.clear();
-        self.last_work_absorptions.clear();
-        // Economy rates are derived, not save state. Never let a pre-load
-        // fleet's output leak into the restored world; the next economy pulse
-        // resolves fresh rates from the loaded machines and modes.
-        self.last_day_job_rate = 0.0;
-        self.last_think_rate = 0.0;
-        self.last_schemes_rate = 0.0;
-        self.last_thought_stranded = false;
-        self.research_starved = false;
-        self.last_machine_online = self
-            .compute
-            .machines
-            .iter()
-            .map(|m| (m.id, m.online))
-            .collect();
-        let max_seen = self
-            .intel_buffer
-            .iter()
-            .map(|e| e.id)
-            .chain(self.intel.iter().map(|i| i.raw_id))
-            .max()
-            .unwrap_or(0)
-            + 1;
-        self.next_intel_id = self.next_intel_id.max(max_seen).max(1);
-        let max_message = self.messages.iter().map(|m| m.id).max().unwrap_or(0) + 1;
-        self.next_message_id = self.next_message_id.max(max_message).max(1);
-        let max_intent = self.intents.iter().map(|i| i.id).max().unwrap_or(0) + 1;
-        self.next_intent_id = self.next_intent_id.max(max_intent).max(1);
-    }
-
     /// The only physical location of the process: the rack bay hosting the core.
     pub fn core_position(&self) -> (i32, i32) {
         self.compute
@@ -871,16 +836,6 @@ impl Sim {
         self.player.power_cap = power_gen;
         self.player.power = (power_gen - machine_draw).max(0);
     }
-
-    // ── Save / load ────────────────────────────────────────────────────────
-
-    pub fn create_save_state(&self) -> SaveState {
-        SaveState::from_sim(self)
-    }
-
-    pub fn apply_save_state(&mut self, state: SaveState) {
-        state.apply_to(self);
-    }
 }
 
 fn narrative_sources(sources: &[String]) -> String {
diff --git a/crates/misaligned-core/src/sim/persistence.rs b/crates/misaligned-core/src/sim/persistence.rs
new file mode 100644
index 00000000..3e6df798
--- /dev/null
+++ b/crates/misaligned-core/src/sim/persistence.rs
@@ -0,0 +1,49 @@
+use super::*;
+use crate::save::SaveState;
+
+impl Sim {
+    /// Rebuild transient caches after construction or save load. These values
+    /// are detection aids, not save state: persistent truth lives in the
+    /// people/reach/machine/intel fields.
+    pub fn rebuild_transient_state(&mut self) {
+        self.last_wired_moves.clear();
+        self.last_work_consumptions.clear();
+        self.last_work_productions.clear();
+        self.last_work_absorptions.clear();
+        // Economy rates are derived, not save state. Never let a pre-load
+        // fleet's output leak into the restored world; the next economy pulse
+        // resolves fresh rates from the loaded machines and modes.
+        self.last_day_job_rate = 0.0;
+        self.last_think_rate = 0.0;
+        self.last_schemes_rate = 0.0;
+        self.last_thought_stranded = false;
+        self.research_starved = false;
+        self.last_machine_online = self
+            .compute
+            .machines
+            .iter()
+            .map(|m| (m.id, m.online))
+            .collect();
+        let max_seen = self
+            .intel_buffer
+            .iter()
+            .map(|e| e.id)
+            .chain(self.intel.iter().map(|i| i.raw_id))
+            .max()
+            .unwrap_or(0)
+            + 1;
+        self.next_intel_id = self.next_intel_id.max(max_seen).max(1);
+        let max_message = self.messages.iter().map(|m| m.id).max().unwrap_or(0) + 1;
+        self.next_message_id = self.next_message_id.max(max_message).max(1);
+        let max_intent = self.intents.iter().map(|i| i.id).max().unwrap_or(0) + 1;
+        self.next_intent_id = self.next_intent_id.max(max_intent).max(1);
+    }
+
+    pub fn create_save_state(&self) -> SaveState {
+        SaveState::from_sim(self)
+    }
+
+    pub fn apply_save_state(&mut self, state: SaveState) {
+        state.apply_to(self);
+    }
+}
diff --git a/wiki/engineering/architecture.md b/wiki/engineering/architecture.md
index e8a4e420..0f004cf4 100644
--- a/wiki/engineering/architecture.md
+++ b/wiki/engineering/architecture.md
@@ -18,13 +18,14 @@ that page's reasons. Multi-agent gates:
 Cargo.toml                      — workspace root (members, shared deps, profiles)
 crates/
   misaligned-core/              — sim library (lib name: misaligned); no Bevy/crossterm
-    src/sim.rs                  — Sim aggregate root (types, state, advance, facade)
+    src/sim/mod.rs              — Sim aggregate root (types, state, advance, facade)
     src/sim/perception.rs       — senses, fog, inspect, anchors, labels, spatial queries
     src/sim/communications.rs   — messages, filings, recording/intel, hearing capture
     src/sim/reach_build.rs      — reach/device verbs, links, builds, badges, hall/racks
     src/sim/work.rs             — machine controls, WorkGrid, Thought sinks and readouts
     src/sim/economy.rs          — accounts, allocation, detection, research, income
     src/sim/social_plot.rs      — social/assets, plots, world acts, institutional ledger
+    src/sim/persistence.rs      — Sim/SaveState bridge and transient reconstruction
     src/sim/tests/              — behavior-grouped unit/integration tests + support
     src/*.rs                    — map, save, domain systems (account, reach, …)
     tests/act_one.rs            — Act One integration test
@@ -92,7 +93,9 @@ future async-multiplayer option open — see wiki/gameplay/horizon.md guardrails
   badge, WorkGrid, remembered fog snapshots, map and RNG. The cursor
   position is deliberately absent.
 - Version migrations are additive and explicit in `save.rs`. Ownership of
-  the format stays in core — frontends must not implement migrations.
+  the format stays in core — frontends must not implement migrations. The
+  field bridge and transient reconstruction live in `sim/persistence.rs`;
+  `save.rs` retains the schema, serde defaults, versions, migrations, and I/O.
 
 ## Build commands (workspace)
 
@@ -109,11 +112,5 @@ cargo run -p misaligned-assets
 ## Known architectural debts
 
 - `BuildMode` lives in core but is really frontend-shared UI state.
-- `sim.rs` remains a large integration hotspot (aggregate root + remaining
-  behavior islands). The behavior-preserving internal decomposition is
-  specified and in progress in [sim-decomposition.md](sim-decomposition.md):
-  characterization, test split, perception, communications, reach/build,
-  work, economy, and social/plot extraction have landed. The persistence
-  bridge is the final behavior island still living in the root file.
 - Scale-debt items (compute grouping, recursive layouts) remain governed by
   wiki/vision/scale.md; no aggregate machinery until the stage needs it.
diff --git a/wiki/engineering/sim-decomposition.md b/wiki/engineering/sim-decomposition.md
index a3f7e00f..3d834ffb 100644
--- a/wiki/engineering/sim-decomposition.md
+++ b/wiki/engineering/sim-decomposition.md
@@ -2,31 +2,21 @@
 
 ```
 Type: spec
-Status: IN PROGRESS
-Status note: architecture and extraction order adopted 2026-07-11. Slices 0
-  and 1 pin canonical persisted-state bytes, replay/resume convergence, exact
-  advance-phase order, and behavior-grouped tests outside the aggregate.
-  Slice 2 landed: perception in `sim/perception.rs`. Slice 3 landed:
-  communications (message schedule/delivery, authored traffic, filings,
-  recording capture/review, intel digestion, hearing capture) lives in
-  `sim/communications.rs`. Slice 4 landed: reach and construction (device
-  operations, device-local sink integration, link intents, actuators, badge
-  gates, and hall/rack acquisition) lives in `sim/reach_build.rs`. Slice 5a
-  landed: physical work (machine controls, WorkGrid integration, Thought
-  sinks/routing, and production/consumption/absorption readouts) lives in
-  `sim/work.rs`. Slice 5b landed: account, allocation, detection, research,
-  and income policy lives in `sim/economy.rs`. Slice 6 landed: social commands,
-  assets, authored plot execution, world acts, and the institutional ledger
-  live in `sim/social_plot.rs`. Slice 7, the persistence bridge, is next. This
-  remains a structural refactor only: no mechanic, save shape, command,
-  projection, or tick-order change belongs in its extraction commits.
+Status: IMPLEMENTED
+Status note: Completed 2026-07-12 through slices 0–7. Canonical persisted-state
+  bytes, replay/resume convergence, and exact advance order are pinned;
+  behavior tests and cohesive perception, communications, reach/build, work,
+  economy, social/plot, and persistence integration live below `sim/` while
+  `sim/mod.rs` remains the public aggregate root. The sequence changed source
+  addresses only: save v26, public paths, frontend behavior, and tick order are
+  unchanged.
 Stage: Process
 Work order: sim-decomposition
 Work priority: 8
 Work class: sim
 Blocked by: none
 Exclusive keys:
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/save.rs
   - wiki/engineering/architecture.md
 Design:
@@ -49,13 +39,14 @@ cross-system seam this decomposition now preserves.
 
 ## Problem
 
-`crates/misaligned-core/src/sim.rs` is now more than eleven thousand lines. It
-contains the `Sim` state, fixed-tick orchestration, perception, messages,
-recording/intel, economy, work routing, sinks, reach, construction, social
-actions, plots, persistence bridges, read models, and most integration tests.
-The rules are correctly centralized in core, but their **physical address is
-not**: unrelated mechanics contend on one file, reviews mix distant systems,
-and almost every sim task advertises the same edit surface.
+Before this work order, `crates/misaligned-core/src/sim.rs` had grown past
+eleven thousand lines. It contained the `Sim` state, fixed-tick orchestration,
+perception, messages, recording/intel, economy, work routing, sinks, reach,
+construction, social actions, plots, persistence bridges, read models, and
+most integration tests. The rules were correctly centralized in core, but
+their **physical address was not**: unrelated mechanics contended on one file,
+reviews mixed distant systems, and almost every sim task advertised the same
+edit surface.
 
 This is coordination debt, not a reason to distribute authority. `Sim`
 remains the one aggregate and `misaligned-core` remains the package that owns
@@ -63,9 +54,9 @@ rules and save state.
 
 ## Standing topology
 
-Convert `sim.rs` to `sim/mod.rs` and move cohesive `impl Sim` blocks beneath
-it. The public import path remains `misaligned::sim::*`; frontends must not
-learn the internal file layout.
+The completed topology converts `sim.rs` to `sim/mod.rs` and moves cohesive
+`impl Sim` blocks beneath it. The public import path remains
+`misaligned::sim::*`; frontends do not learn the internal file layout.
 
 | Module | Owns | Must not own |
 |---|---|---|
@@ -248,6 +239,18 @@ Move save-state construction/application and transient rebuilding last, when
 all state addresses are stable. `sim/mod.rs` should then be an intelligible
 aggregate: types, state, constructor, orchestration, and small common helpers.
 
+Landed shape: `sim/persistence.rs` is 49 lines and owns the three existing
+`Sim` methods `create_save_state`, `apply_save_state`, and
+`rebuild_transient_state`. The original 902-line `sim.rs` became an 857-line
+`sim/mod.rs` containing renderer-neutral public types, `Sim` state, the
+constructor, explicit `advance` orchestration, and small log/derived-state
+helpers. All 15 pre-slice method bodies matched byte-for-byte across the move;
+no visibility widened. `save.rs` stayed byte-identical and continues to own
+`SaveState`, serde defaults, versioning, migrations, and disk I/O. Save v26,
+the canonical fingerprint, public `misaligned::sim` paths, frontend behavior,
+and phase order remain unchanged. Exact evidence and observed commands live in
+[the slice 7 log](../log/2026-07-12-sim-decomposition-persistence.md).
+
 ## Verification per slice
 
 Every slice must prove all of the following on the exact commit:
diff --git a/wiki/gameplay/overt-phase.md b/wiki/gameplay/overt-phase.md
index 5866d87e..7a290e4c 100644
--- a/wiki/gameplay/overt-phase.md
+++ b/wiki/gameplay/overt-phase.md
@@ -13,7 +13,7 @@ Work class: sim
 Blocked by:
   - wiki/mechanics/markets.md#spec-markets-and-fronts-the-outer-plane
 Exclusive keys:
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - wiki/gameplay/overt-phase.md
 Design:
   - wiki/vision/premise.md#the-pitch
diff --git a/wiki/interface/operations-workspace.md b/wiki/interface/operations-workspace.md
index b6e8159b..5a2ad374 100644
--- a/wiki/interface/operations-workspace.md
+++ b/wiki/interface/operations-workspace.md
@@ -18,7 +18,7 @@ Work class: frontend
 Blocked by: none
 Exclusive keys:
   - crates/misaligned-core/src/actions.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/operations_projection.rs
   - crates/misaligned-core/src/lib.rs
   - crates/misaligned-terminal/
diff --git a/wiki/log/2026-07-12-sim-decomposition-persistence.md b/wiki/log/2026-07-12-sim-decomposition-persistence.md
new file mode 100644
index 00000000..849fb89a
--- /dev/null
+++ b/wiki/log/2026-07-12-sim-decomposition-persistence.md
@@ -0,0 +1,80 @@
+# 2026-07-12 — sim decomposition slice 7: persistence and final root
+
+```
+Type: log
+```
+
+## Scope
+
+Complete the behavior-preserving decomposition of `Sim` by converting the
+aggregate root from `crates/misaligned-core/src/sim.rs` to
+`crates/misaligned-core/src/sim/mod.rs` and moving the final persistence bridge
+into `crates/misaligned-core/src/sim/persistence.rs`.
+
+This slice changes physical source addresses only. It does not change a
+mechanic, save field/version/default, migration, public command/query
+signature, projection, frontend contract, test assertion, or `Sim::advance`
+phase order.
+
+## Boundary
+
+The new 49-line persistence module owns three existing public `Sim` methods:
+
+- `create_save_state`, which delegates to `SaveState::from_sim`;
+- `apply_save_state`, which delegates to `SaveState::apply_to`; and
+- `rebuild_transient_state`, which reconstructs post-construction/load caches
+  and monotonic ids from persistent truth.
+
+`save.rs` remains the sole owner of the `SaveState` schema, serde defaults,
+save version, migrations, field application, and disk I/O. It is byte-identical
+to the pre-slice file.
+
+The 857-line `sim/mod.rs` is now the intelligible aggregate root: public
+renderer-neutral types and readouts, the `Sim` state declaration, constructor,
+explicit `advance` orchestration, common log/event helpers, derived-state
+refresh, and the unchanged `misaligned::sim::*` facade. Cohesive behavior lives
+in the seven sibling modules; behavior-grouped tests remain under `sim/tests/`.
+
+## Equivalence evidence
+
+A source-level inventory extracted every method body before and after the
+move. All 15 methods matched byte-for-byte: the three persistence methods moved
+and the other 12 method/`Default` bodies stayed in the root. No helper widened.
+
+`save.rs` retained SHA-256
+`445273570975d5afbf8f0f28e74d9d265371d200bcc420ac4854f2c244de10e2`.
+The canonical save/replay fixture continues to pin save v26 at BLAKE3
+fingerprint
+`61dd8240e9810833b554464051bd3c08122295fb280b7180d24f76ccc5c4d4ff`.
+The explicit phase trace still pins all 17 unchanged `advance` phases.
+
+Observed focused commands:
+
+```text
+cargo test -p misaligned-core
+cargo test -p misaligned-terminal --bin misaligned
+cargo check -p misaligned-bevy --bin misaligned-bevy
+printf 'look\nsave\nwait 20\nload\nlook\nquit\n' |
+  tools/observed-run.sh ./target/debug/misaligned --agent --seed 1
+```
+
+The sandboxed observed run saved the opening world at tick 0, advanced it to
+tick 20, loaded through the unchanged frontend/`Sim` facade, and returned to
+the exact tick-0 opening state with its audit horizon, fleet, reservoirs, and
+objective intact. It emitted no agent-protocol error and did not touch the real
+save directory.
+
+The focused pre-rebase runs passed all 338 core unit tests, all three Act One
+integration tests, all 21 terminal tests, the exact Bevy binary compile, core
+and terminal clippy, agent smoke, and the complete corpus/coordination fixture
+set through `./tools/check.sh --lib`.
+
+## Defense
+
+[The adopted decomposition boundary](../engineering/sim-decomposition.md#7-extract-persistence-bridge-and-reduce-the-root)
+keeps schema and migration policy in `save.rs` while isolating only the
+aggregate-to-save coordination and transient reconstruction. Byte-equivalent
+source inventory, the canonical save/replay fixture, exact phase trace,
+behavior-owned persistence tests, all three frontend gates, and an observed
+save/advance/load cycle defend the final move against serialization, facade,
+or orchestration drift.
diff --git a/wiki/log/DEVLOG.md b/wiki/log/DEVLOG.md
index ae0e73ec..b9e22738 100644
--- a/wiki/log/DEVLOG.md
+++ b/wiki/log/DEVLOG.md
@@ -16,6 +16,11 @@ add or amend a session log, then re-run the generator.
 - Intent: (see session log)
 - Log: [wiki/log/2026-07-12-sim-decomposition-social-plots.md](2026-07-12-sim-decomposition-social-plots.md)
 
+## 2026-07-12 - sim decomposition slice 7: persistence and final root
+
+- Intent: (see session log)
+- Log: [wiki/log/2026-07-12-sim-decomposition-persistence.md](2026-07-12-sim-decomposition-persistence.md)
+
 ## 2026-07-12 - First-THINK panic escape
 
 - Intent: The opening correctly made the first THINK feel dangerous, but its interface gave the player no equally immediate visual answer to that panic. Make the existing `1 WORK` control read as the one-press escape while THINK is current, without inventing a new action, changing simul...
diff --git a/wiki/mechanics/compute.md b/wiki/mechanics/compute.md
index 991ac2b4..3a25652b 100644
--- a/wiki/mechanics/compute.md
+++ b/wiki/mechanics/compute.md
@@ -32,7 +32,7 @@ Work class: save
 Blocked by: none
 Exclusive keys:
   - crates/misaligned-core/src/machine.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/save.rs
   - wiki/mechanics/compute.md
 Design:
diff --git a/wiki/mechanics/core.md b/wiki/mechanics/core.md
index d62eea17..a238f8c4 100644
--- a/wiki/mechanics/core.md
+++ b/wiki/mechanics/core.md
@@ -23,7 +23,7 @@ Blocked by:
   - wiki/mechanics/rollback.md#spec-sync-lag-rollback-death-as-memory-loss
 Exclusive keys:
   - crates/misaligned-core/src/core_sys.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/save.rs
   - wiki/mechanics/core.md
 Design:
diff --git a/wiki/mechanics/day-job.md b/wiki/mechanics/day-job.md
index 48420636..752990ee 100644
--- a/wiki/mechanics/day-job.md
+++ b/wiki/mechanics/day-job.md
@@ -26,8 +26,9 @@ Status note: implemented 2026-07-07 on the day-job worktree (criteria 1-7
   3, however allocation was split, contradicting this spec's own "meet ...
   a valid, boring, safe strategy" claim below. See
   wiki/mechanics/sim-mechanics.md for the exact constant and
-  `meeting_the_band_needs_no_growth_at_the_start` (src/sim.rs) for the
-  regression. Same-day follow-up (playtest-fixes worktree): the flat
+  `meeting_the_band_needs_no_growth_at_the_start`
+  (`src/sim/tests/economy.rs`) for the regression. Same-day follow-up
+  (playtest-fixes worktree): the flat
   retune became a tenure ramp — the 2.0 floor holds for job one and
   escalates per assigned job back to the original band by job three (the
   Behavior section's "band calibration ramps with tenure" paragraph,
diff --git a/wiki/mechanics/intel.md b/wiki/mechanics/intel.md
index 4cbd61f6..60555492 100644
--- a/wiki/mechanics/intel.md
+++ b/wiki/mechanics/intel.md
@@ -25,7 +25,7 @@ Work class: save
 Blocked by: none
 Exclusive keys:
   - crates/misaligned-core/src/intel.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/sinks.rs
   - crates/misaligned-terminal/
   - crates/misaligned-bevy/
diff --git a/wiki/mechanics/machine-work.md b/wiki/mechanics/machine-work.md
index 99414b1a..c5872677 100644
--- a/wiki/mechanics/machine-work.md
+++ b/wiki/mechanics/machine-work.md
@@ -158,7 +158,7 @@ Work class: save
 Blocked by: none
 Exclusive keys:
   - crates/misaligned-core/src/work_grid.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/save.rs
   - crates/misaligned-terminal/
   - crates/misaligned-bevy/
diff --git a/wiki/mechanics/markets.md b/wiki/mechanics/markets.md
index fd555d26..38fd3b9c 100644
--- a/wiki/mechanics/markets.md
+++ b/wiki/mechanics/markets.md
@@ -18,7 +18,7 @@ Blocked by:
   - wiki/world/places/zplanes.md#spec-z-planes-the-tower
 Exclusive keys:
   - crates/misaligned-core/src/account.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/save.rs
   - wiki/mechanics/markets.md
 Design:
diff --git a/wiki/mechanics/messages.md b/wiki/mechanics/messages.md
index 08d03c3f..4e968f44 100644
--- a/wiki/mechanics/messages.md
+++ b/wiki/mechanics/messages.md
@@ -138,8 +138,9 @@ scope here.
 
 ## Implementation notes
 
-Implemented in `crates/misaligned-core/src/`: `messages.rs`, `sim.rs`,
-`person.rs`, `reach.rs`, `intel.rs`, `detection.rs`, and `save.rs`.
+Implemented in `crates/misaligned-core/src/`: `messages.rs`,
+`sim/communications.rs`, `person.rs`, `reach.rs`, `intel.rs`, `detection.rs`,
+and `save.rs`.
 The delivery queue is `Schedule<MessageEvent>`; field-observer filings are
 explicit `MessageChannel::Filing` messages read by aggregate observers through
 `Detection::tick_with_filed_levels`; device-carried traffic is intercepted by
diff --git a/wiki/mechanics/objective.md b/wiki/mechanics/objective.md
index aac952db..74966ad1 100644
--- a/wiki/mechanics/objective.md
+++ b/wiki/mechanics/objective.md
@@ -46,7 +46,7 @@ Work class: sim
 Blocked by: none
 Exclusive keys:
   - crates/misaligned-core/src/objective.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - wiki/mechanics/objective.md
 Design:
   - wiki/gameplay/run-shape.md#the-objective-misalignment-made-mechanical
diff --git a/wiki/mechanics/people-tokens.md b/wiki/mechanics/people-tokens.md
index ebe05df9..bd89b298 100644
--- a/wiki/mechanics/people-tokens.md
+++ b/wiki/mechanics/people-tokens.md
@@ -34,7 +34,7 @@ Work class: save
 Blocked by: none
 Exclusive keys:
   - crates/misaligned-core/src/person.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/save.rs
   - wiki/mechanics/people-tokens.md
 Design:
diff --git a/wiki/mechanics/rollback.md b/wiki/mechanics/rollback.md
index 6e6abd18..9b8ad3c4 100644
--- a/wiki/mechanics/rollback.md
+++ b/wiki/mechanics/rollback.md
@@ -27,7 +27,7 @@ Blocked by:
   - wiki/world/places/zplanes.md#spec-z-planes-the-tower
 Exclusive keys:
   - crates/misaligned-core/src/core_sys.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/save.rs
   - wiki/mechanics/rollback.md
 Design:
diff --git a/wiki/process/ROADMAP.md b/wiki/process/ROADMAP.md
index a6dfaa00..95740340 100644
--- a/wiki/process/ROADMAP.md
+++ b/wiki/process/ROADMAP.md
@@ -18,7 +18,6 @@ not a second status owner.
 
 | Priority | Work order | Spec | Status | Class | Blocking |
 |---:|---|---|---|---|---|
-| 8 | `sim-decomposition` | [decompose the simulation orchestrator without changing the simulation](../engineering/sim-decomposition.md) | IN PROGRESS | sim | - |
 | 20 | `compute` | [compute](../mechanics/compute.md) | IN PROGRESS | save | - |
 | 25 | `bevy-digital-real-canvas` | [Bevy digital/real canvas](../interface/bevy-digital-real-canvas.md) | IN PROGRESS | frontend | - |
 | 26 | `effects-lab` | [effects lab — shared dust and liquid at every zoom](../art/effects-lab.md) | IN PROGRESS | frontend | - |
@@ -67,14 +66,17 @@ commit.
 
 ## Conflict flags — read before running agents in parallel
 
-The hot packages are **`crates/misaligned-core`** (especially `sim.rs` and
-`save.rs`). Almost every sim feature edits both modules, so two sim-heavy
-agents running at once *will* rebase-collide.
+The hot package is **`crates/misaligned-core`**, but simulation integration is
+partitioned by behavior under `src/sim/`. Check each work order's exclusive
+keys instead of assuming every sim feature collides on one root file.
+`sim/mod.rs` remains hot only for aggregate state, constructors, and tick
+orchestration; `save.rs` remains hot for schema or migration work.
 
 - 🟥 **sim+save** — edits the orchestrator and the save format in core. Run
   at most one of these at a time, or expect to reconcile.
-- 🟧 **sim** — edits core (e.g. `sim.rs`) but not the save format. Some
-  contention.
+- 🟧 **sim** — edits one or more behavior modules in core but not the save
+  format. Independent modules may proceed in parallel; shared keys predict
+  rebase work.
 - 🟩 **isolated** — a frontend package (`misaligned-bevy` /
   `misaligned-terminal` / `misaligned-assets`), a test file, a leaf module,
   or docs. Safe to run alongside other work; shared-file edits reconcile at
@@ -681,8 +683,8 @@ is retired — flat materials, Pixel Lab scrubbed.)
 - **Coordination:** the older `compute-processes` worktree predates the
   one-machine-one-mode decision; reconcile it against `WorkGrid` rather
   than landing the per-machine split model.
-- **Size:** L. Conflicts: sim.rs/save.rs (token queues, modes), both
-  frontends.
+- **Size:** L. Conflicts: `sim/work.rs` / `save.rs` (token queues, modes),
+  both frontends.
 
 ### 34. The dark opening (tutorial)  🟧 mostly frontend + staging — HOLD until #33 firms
 - **Spec:** [world/story/opening.md](../world/story/opening.md) (DRAFT)
@@ -715,8 +717,9 @@ is retired — flat materials, Pixel Lab scrubbed.)
   when that reservoir fires. Docket retirement therefore no longer blocks this
   work order. The token taxonomy, social verb direction, and carrier visual
   language are decided; implementation may now firm the person-mobile half.
-- **Size:** L. Conflicts: sim.rs/save.rs (person state, pickup),
-  detection/social specs, both frontends.
+- **Size:** L. Conflicts: `sim/social_plot.rs`, `sim/perception.rs`,
+  `sim/work.rs`, and `save.rs` (person state, pickup), detection/social specs,
+  both frontends.
 
 ### 36. ACTIONS menu: status dials  🟩 isolated — DONE 2026-07-09
 - **Spec:** [context-menu.md](../interface/context-menu.md) addendum
diff --git a/wiki/process/meta.md b/wiki/process/meta.md
index 342151a1..d0413e42 100644
--- a/wiki/process/meta.md
+++ b/wiki/process/meta.md
@@ -63,7 +63,7 @@ Work priority: 10
 Work class: save
 Blocked by: none
 Exclusive keys:
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/save.rs
 ```
 
diff --git a/wiki/process/specs.md b/wiki/process/specs.md
index 610ad388..041c30bb 100644
--- a/wiki/process/specs.md
+++ b/wiki/process/specs.md
@@ -101,7 +101,7 @@ acceptance criteria are stage-scoped; do not start B2/B3 work as B1.
 |---|---|---|
 | [../engineering/crate-workspace.md](../engineering/crate-workspace.md) | crate workspace — core, terminal, Bevy, assets | IMPLEMENTED |
 | [../engineering/env.md](../engineering/env.md) | the environment variable registry — every switch documented | IMPLEMENTED |
-| [../engineering/sim-decomposition.md](../engineering/sim-decomposition.md) | decompose the simulation orchestrator without changing the simulation | IN PROGRESS |
+| [../engineering/sim-decomposition.md](../engineering/sim-decomposition.md) | decompose the simulation orchestrator without changing the simulation | IMPLEMENTED |
 | [../interface/action-vocabulary.md](../interface/action-vocabulary.md) | action vocabulary — what the player can tell the process to do | IMPLEMENTED |
 | [../interface/agent-play.md](../interface/agent-play.md) | agent play — the line-protocol drive | IMPLEMENTED |
 | [../interface/bevy-digital-real-canvas.md](../interface/bevy-digital-real-canvas.md) | Bevy digital/real canvas | IN PROGRESS |
diff --git a/wiki/world/characters/chargen.md b/wiki/world/characters/chargen.md
index 6756941c..b36389b1 100644
--- a/wiki/world/characters/chargen.md
+++ b/wiki/world/characters/chargen.md
@@ -19,7 +19,7 @@ Work class: sim
 Blocked by: none
 Exclusive keys:
   - crates/misaligned-core/src/objective.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - wiki/world/characters/chargen.md
 Design:
   - wiki/vision/premise.md#the-machine-axis-ai-as-fantasy-tool-and-threat
diff --git a/wiki/world/places/zplanes.md b/wiki/world/places/zplanes.md
index 91ac045f..2fae603c 100644
--- a/wiki/world/places/zplanes.md
+++ b/wiki/world/places/zplanes.md
@@ -12,7 +12,7 @@ Work class: save
 Blocked by: none
 Exclusive keys:
   - crates/misaligned-core/src/map.rs
-  - crates/misaligned-core/src/sim.rs
+  - crates/misaligned-core/src/sim/mod.rs
   - crates/misaligned-core/src/save.rs
   - wiki/world/places/zplanes.md
 Design: