fix(v0.3.1): sated bot stops chasing food + perf-leak + fuzzy improvement dedup

Third day of "bot just walks back and forth burning tokens". Root
causes were mechanical, not the manifesto:

1. SATED BOT CHASING FOOD (the big one)
   Bot had food=17 (nearly full) but storyline first_food + manifesto
   L1 required 2+ food ITEMS in inventory, so it looped scout-food /
   acquire-food for hours instead of working. Now both treat a hunger
   bar >= 14 (SATED_FOOD) as satisfied even with empty food inventory —
   a full bot chops wood / makes tools and grabs food opportunistically,
   only hard-pursuing food when actually hungry (< 14).
   manifesto/needs.js foodDetect + goal/storyline.js first_food.completed.

2. perf_hooks MEMORY LEAK (overnight OOM suspect)
   "MaxPerformanceEntryBufferExceededWarning: 1,000,001 measure entries".
   mineflayer/pathfinder emit perf marks we never consume. Added a
   60s reaper in bot.js (performance.clearMeasures/clearMarks). unref'd.

3. IMPROVEMENT QUEUE SELF-DUPLICATING
   The LLM re-filed closed gaps with reworded titles (#5/#8/#9 were
   dupes of implemented #1/#2/#3). Exact-title dedup missed them.
   Replaced with token-set fuzzy match (isDuplicateTitle): jaccard>=0.75
   OR >=3 shared meaningful tokens with jaccard>=0.5. Also: a re-filed
   gap that's already implemented/rejected is NOT resurrected as a new
   open row. Cleared all 5 open requests (now genuinely implemented).

Also confirmed (no change needed):
- canDig=true is a DELIBERATE codebase-wide choice ("without it the bot
  gets permanently stuck", actions.js). The stale memory recommending
  canDig=false is updated. ViaBackwards dig works partially (dug:1
  moved:1.8 observed); false would trap the bot in every pit.
- scout-food already has blind/tunnel fallback + 12s step timeout
  (operator's earlier edits) so trapped-pathfinder degrades instead of
  hanging 30s.

Tests: 407 green (was 404). Updated needs/state/storyline tests for the
SATED_FOOD threshold; added fuzzy-dedup + tokenize/jaccard tests.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

runtime/bot.js

@@ -946,6 +946,25 @@ function tick() {
 function startTickLoop() {
 	if (tickTimer) clearInterval(tickTimer);
 	tickTimer = setInterval(tick, config.tickIntervalMs);
+	startPerfBufferReaper();
+}
+
+// mineflayer + mineflayer-pathfinder emit performance.mark/measure
+// entries that accumulate in the global perf_hooks buffer with no
+// upper bound. Over a multi-hour run this grew past 1,000,000 entries
+// ("MaxPerformanceEntryBufferExceededWarning") and is a prime suspect
+// for the overnight OOM. We don't consume those entries, so clear the
+// buffer on a slow interval.
+let perfReaperTimer = null;
+function startPerfBufferReaper() {
+	if (perfReaperTimer) return;
+	perfReaperTimer = setInterval(() => {
+		try {
+			performance.clearMeasures?.();
+			performance.clearMarks?.();
+		} catch {}
+	}, 60_000);
+	perfReaperTimer.unref?.();
 }
 
 // ---- IPC commands ----------------------------------------------------------