fix(copaw): retry prompt reads during worker startup

[RerankerGuo]

Summary

• add a bounded stable UTF-8 prompt reader for CoPaw worker SOUL.md / AGENTS.md materialization
• use it during startup and config re-bridge so transient mc mirror/read races do not crash the worker
• add focused unit coverage and changelog entry

Tests

• git diff --check
• python3 -m py_compile copaw/src/copaw_worker/worker.py copaw/tests/test_worker_health.py
• not run: python3 -m pytest copaw/tests/test_worker_health.py -q (pytest is not installed in this environment)

Fixes #711.
Also addresses #728.

[github-actions]

📊 CI Metrics Report

Summary

Metric	Current	Baseline	Change
LLM Calls	132	81	+51 ↑ +63.0%
Input Tokens	3343825	2803871	+539954 ↑ +19.3%
Output Tokens	33300	16791	+16509 ↑ +98.3%
Total Tokens	3377125	2820662	+556463 ↑ +19.7%

By Role

Role	Metric	Current	Baseline	Change
🧠 Manager	LLM Calls	88	68	+20 ↑ +29.4%
	Input Tokens	2211583	2502214	-290631 ↓ -11.6%
	Output Tokens	15233	13725	+1508 ↑ +11.0%
	Total Tokens	2226816	2515939	-289123 ↓ -11.5%
🔧 Workers	LLM Calls	44	13	+31 ↑ +238.5%
	Input Tokens	1132242	301657	+830585 ↑ +275.3%
	Output Tokens	18067	3066	+15001 ↑ +489.3%
	Total Tokens	1150309	304723	+845586 ↑ +277.5%

Per-Test Breakdown

Test	Mgr Calls	Wkr Calls	Δ Calls	Mgr In	Wkr In	Mgr Out	Wkr Out	Δ Tokens	Trend
02-create-worker	9	0	-3 ↓ -25.0%	246069	0	1020	0	-111533 ↓ -31.1%	✅ improved
03-assign-task	6	0	-9 ↓ -60.0%	176112	0	1140	0	-296404 ↓ -62.6%	✅ improved
04-human-intervene	10	10	+7 ↑ +53.8%	249626	246541	1872	1342	+66383 ↑ +15.3%	⚠️ regressed
05-heartbeat	6	4	+3 ↑ +42.9%	166631	105179	1132	876	-1434 ↓ -0.5%	⚠️ regressed
06-multi-worker	57	30	+53 ↑ +155.9%	1373145	780522	10069	15849	+899451 ↑ +70.3%	⚠️ regressed

Trends

✅ 2 test(s) improved (fewer LLM calls)
⚠️ 3 test(s) regressed (more LLM calls)

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Generated by HiClaw CI on 2026-07-08 06:52:27 UTC

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📦 Download debug logs & test artifacts

[RerankerGuo]

@shiyiyue1102 Hi! This PR addresses #711 / #728. Just rebased onto current main (was conflicting) — CI is now green (18/18). Adds bounded stable UTF-8 reads for SOUL.md / AGENTS.md during CoPaw startup and re-bridge, with replacement-decoding fallback. Could you take a look when convenient?