fix(campaign): harden policy edit proposer edges

[drewstone]

Summary

• fix policyEditProposer zero-candidate caps so populationSize=0 returns no candidates before applying edits
• tighten PolicyEdit validation for finite confidence and non-empty source attribution ids
• make text append/prepend idempotency exact block/line based instead of substring based
• add coverage for static typed edits, caps, same-surface skips, CodeSurface passthrough, invalid surfaces, prepend/merge modes, and admission options

Addresses follow-up findings from #286: #286 (comment)

Verification

• pnpm exec vitest run tests/policy-edit.test.ts tests/campaign/policy-edit-proposer.test.ts
• pnpm typecheck
• pnpm test
• git merge-tree --write-tree origin/main HEAD

[tangletools]

✅ Auto-approved drewstone PR — f8f8190d

This PR was opened by the trusted drewstone account.
The full PR reviewer audit still runs separately and will publish findings if it detects issues.

_{tangletools · auto-approval · reason: drewstone_author · 2026-06-29T23:25:20Z}

[tangletools]

⚪ Value Audit — audit-incomplete

Verdict	audit-incomplete
Concerns	0 (none)
Heuristic	0.0s
Duplication	0.0s
Interrogation	10.5s (2 bridge agents)
Total	10.5s

💰 Value — error

value agent produced no parseable value-audit JSON.

• Model: opencode/deepseek/deepseek-v4-pro
• Bridge attempts: 3
• Bridge error: opencode/kimi-for-coding/k2p7: bridge stream ended without value-audit content; opencode/zai-coding-plan/glm-5.2: bridge stream ended without value-audit content; opencode/deepseek/deepseek-v4-pro: bridge stream ended without value-audit content

🎯 Usefulness — error

usefulness agent produced no parseable value-audit JSON.

• Model: opencode/deepseek/deepseek-v4-pro
• Bridge attempts: 3
• Bridge error: opencode/zai-coding-plan/glm-5.2: bridge stream ended without value-audit content; opencode/kimi-for-coding/k2p7: bridge stream ended without value-audit content; opencode/deepseek/deepseek-v4-pro: bridge stream ended without value-audit content

No PR concerns were produced because the value/usefulness agent pass did not complete. Treat this audit as incomplete, not as approval.

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What this audit checks

It judges the change on its merits — not whether it was tasked out in an issue. Unticketed, fast-moving work is fine; the question is whether the change is good and whether a better or existing approach should be used instead.

Pass	What it asks
Heuristic	Vague title? Whitespace-only or cruft-bearing diff? (content signals only)
Duplication	Do added function/class names already exist elsewhere in the repo?
Value Audit	What does it do? What goal does it achieve? Is it good? Better architecture or already-exists?
Usefulness Audit	Does it integrate and fit? Will it hold up in real use and actually get used?

Findings are concerns, not blocks — the human reviewer decides what to do with them.

_{value-audit · 20260629T232719Z}