diff --git a/docs/tickets/todo/002-fixed-step-replay.md b/docs/tickets/todo/002-fixed-step-replay.md
--- a/docs/tickets/todo/002-fixed-step-replay.md
+++ b/docs/tickets/todo/002-fixed-step-replay.md
@@ -31,7 +31,7 @@
 - Advance gameplay only through fixed simulation ticks.
 - Keep variable rendering independent from simulation advancement.
 - Track a monotonically increasing simulation tick for the current run.
-- Define a normalized `Input_Command` or equivalent per simulation tick.
+- Define a normalized, quantized `Input_Command` or equivalent per simulation tick.
 - Record one input command per simulated tick for a run.
 - Provide a way to replay a recorded command stream from tick `0` into a fresh simulation state.
 - Add deterministic test coverage for replay behavior without requiring Raylib rendering.
@@ -41,11 +41,13 @@
 - Treat `sim_tick` as the only authoritative gameplay mutation path.
 - Store gameplay timers as integer ticks, not seconds.
 - Avoid authoritative simulation dependence on pointer addresses, unordered iteration, global random state, wall-clock time, render frame count, or raw struct memory layout.
+- Replace or wrap the current float-based command axes before they become persistent replay data.
 - Prefer quantized/integer/fixed-point simulation values for replay-relevant state. Rendering may convert simulation state to floats later.
 
 ## Suggested Implementation Direction
 
-- Use an accumulator in `game_update` or an app-level update function.
+- Add the fixed-step accumulator to app/game state, not `Sim_State`; frame time is an app concern, while ticks are a simulation concern.
+- Use the accumulator in `game_update` or an app-level update function to produce `0..MAX_TICKS_PER_FRAME` simulation ticks per rendered frame.
 - Clamp frame delta to avoid huge catch-up spikes.
 - Cap max simulation ticks per rendered frame to avoid death spirals.
 - Store timers as ticks, not seconds, for gameplay-relevant state.
diff --git a/docs/tickets/todo/003-headless-run-harness.md b/docs/tickets/todo/003-headless-run-harness.md
--- a/docs/tickets/todo/003-headless-run-harness.md
+++ b/docs/tickets/todo/003-headless-run-harness.md
@@ -14,7 +14,7 @@
 
 ## Requirements
 
-- Add a headless executable or `just` recipe that runs `src/sim` without Raylib.
+- Add a headless executable package and `just` recipe that run `src/sim` without Raylib.
 - Accept a small deterministic input script or hard-coded fixture format for prototype runs.
 - Convert scripted input into the same normalized simulation command type used by replay.
 - Emit a stable text transcript with tick-indexed simulation facts.
@@ -23,6 +23,8 @@
 - Keep the transcript derived from simulation state. It must not become the authoritative replay source.
 - Add at least one fixture that can be re-run from the command line.
 - Keep the harness small and deleteable if a better test runner replaces it later.
+
+Suggested location: `src/lib/headless` or another small package outside `src/sim` that imports simulation code but no renderer/platform code.
 
 ## Suggested Script Shape