fix(coding-agents): stop promising automatic correction supersession

[PaleRoses]

Problem

The coding-agent SessionStart preamble says that newer facts supersede older ones. Its skill promises that one correction permanently outranks the stale memory. Ingesting a correction does not establish either guarantee: it adds evidence, but does not directly rewrite the stored knowledge page or guarantee retrieval precedence. An agent can therefore leave the current answer wrong while believing that ingest alone repaired it.

Change

• Keep the existing correction workflow: record what memory claimed, the verified correction, and its evidence with hindsight_ingest_document.
• Explicitly distinguish recording evidence from rewriting a page or guaranteeing ranking.
• Tell the agent to state the verified correction in its current answer as well.
• Regenerate skill/SKILL.md from skill-src/preamble.md using the existing generator.

Three files only: skill source, generated skill, and src/core/knowledge-injection.ts. No storage, retrieval, consolidation, API, stale-page flags, or ingestion-wait behavior changes. Independent of #4170.

Verification

On an isolated worktree based on upstream 9e6d9e7:

• npm ci --ignore-scripts
• npm run skill:build; node scripts/build-skill.mjs --check
• npm test: 879 tests passed across 67 files
• npx tsc --noEmit: clean
• npm run build: success
• prettier --check on all three changed files: clean
• Executed buildKnowledgePreamble with both an empty and populated page roster. A throwaway check rejects the old supersession promise before the patch and passes afterward; both rendered outputs retain correction ingestion and tell the agent to state the correction. No permanent test added solely to pin prose.

No live LLM calls or backend behavior claims. Prepared with automated assistance; the commands above were executed against this PR's tree.

[nicoloboschi]

yes it does because the consolidation will update the existing Observations, that's why it's all based on Knowledge Pages which defaults to Observations only!

[PaleRoses]

You're right. This PR generalizes ingestion-time behavior to the full correction lifecycle and misses the observation-update/page-refresh path. _apply_update_action rewrites existing observations; knowledge pages default to fact_types: ["observation"] and refresh_after_consolidation: true. The replacement wording is misleading for that workflow. Agreed with closing this PR.