fix(server): address PR #23 review — 4 critical bugs, 3 warnings, 11 suggestions

Critical fixes:
- Add PendingRecognitionWire serialization roundtrip test
- Check Option return from delay.cancel() before logging
- InputQueue capacity limit (1000) with drop-oldest and warning
- TODO in observation.rs references ticket #450

Warning fixes:
- Hot-reload guards against invalid/empty content root
- Location header mismatch warning in line pool indexing
- walk_yaml() depth limit (100) against symlink loops
- Consecutive reload failure counter (warns after 5+)

Test additions:
- Negative prerequisite filtering test for monologue lines
- Integration test for pending_recognitions in observer snapshot
- Eavesdrop threshold ordering assertion (Careful < default)

Documentation:
- Playtesting expectation comments on delay constants
- is_pending() scalability note for future NPC cognitive delay
- ID format regex validation in line pool spec
- BTreeMap vs sort() ordering clarification in loader
- Multiplayer TODO in relationships.rs references D-010
- ContentSlug ticket #452 filed for entity slug resolution

394 tests, 0 failures.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/simulation/input.rs

@@ -14,6 +14,10 @@ use crate::simulation::time::{SimulationTime, TickRate};
 use bevy_ecs::prelude::*;
 use std::collections::VecDeque;
 
+/// Maximum number of inputs the queue will hold before dropping oldest.
+/// Prevents unbounded memory growth from input flooding.
+pub const INPUT_QUEUE_CAPACITY: usize = 1000;
+
 /// Queue of pending player inputs, ordered by tick
 #[derive(Resource, Debug, Default)]
 pub struct InputQueue {
@@ -24,6 +28,7 @@ impl InputQueue {
     /// Add a new input to the queue.
     /// Inputs must be pushed in tick order for deterministic processing.
     /// Panics in debug builds if tick ordering is violated.
+    /// Drops oldest inputs when capacity is exceeded.
     pub fn push(&mut self, input: PlayerInput) {
         debug_assert!(
             self.queue.back().is_none_or(|last| last.tick <= input.tick),
@@ -31,6 +36,14 @@ impl InputQueue {
             self.queue.back().map_or(0, |last| last.tick),
             input.tick,
         );
+        if self.queue.len() >= INPUT_QUEUE_CAPACITY {
+            let dropped = self.queue.pop_front();
+            tracing::warn!(
+                "InputQueue at capacity ({}), dropping oldest input (tick={})",
+                INPUT_QUEUE_CAPACITY,
+                dropped.map_or(0, |d| d.tick),
+            );
+        }
         self.queue.push_back(input);
     }
 

server/src/simulation/listening.rs

@@ -91,6 +91,13 @@ pub fn update_listening_focus(
 
         // Sprint stance: stationary but too high-alert to listen
         let Some(threshold) = ListeningFocus::threshold_for_stance(stance) else {
+            if focus.eavesdrop_target.is_some() || focus.stationary_ticks > 0 {
+                tracing::debug!(
+                    "Sprint stance resets eavesdrop: stationary_ticks={}, had_target={}",
+                    focus.stationary_ticks,
+                    focus.eavesdrop_target.is_some(),
+                );
+            }
             focus.stationary_ticks = 0;
             focus.eavesdrop_target = None;
             continue;
@@ -426,6 +433,23 @@ mod tests {
         assert_eq!(focus.stationary_ticks, EAVESDROP_THRESHOLD);
     }
 
+    // -----------------------------------------------------------------------
+    // Constant invariants
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn eavesdrop_threshold_careful_less_than_normal() {
+        // T4: The careful threshold MUST be strictly less than the normal
+        // threshold — careful stance rewards patience with faster eavesdrop
+        // activation (D-053, D-018).
+        assert!(
+            EAVESDROP_THRESHOLD_CAREFUL < EAVESDROP_THRESHOLD,
+            "EAVESDROP_THRESHOLD_CAREFUL ({}) must be < EAVESDROP_THRESHOLD ({})",
+            EAVESDROP_THRESHOLD_CAREFUL,
+            EAVESDROP_THRESHOLD,
+        );
+    }
+
     // -----------------------------------------------------------------------
     // Edge cases
     // -----------------------------------------------------------------------