🧹 Pre-release hygiene sweep: stale docs/versions + simplification + DETERMINISM/prompt-grade audit (second-last)

[ZaxShen]

Sequencing: this is the SECOND-LAST issue of v0.8.4 — run it only after every other milestone issue is solved and merged to dev, and immediately BEFORE the version-bump issue (the last issue).

A pre-release hygiene sweep over the whole plugin repo. This cycle moved/changed a lot (architecture edits; L7 + benchmark content moved from plugin/ → the benchmarks/ repo via #593/#595; swe default model flip #594; attribution footer #601; several hook/MCP fixes), so prose and structure can have drifted.

Scope

1. Stale versions / content across all docs

• No doc references the deleted docs/contributing/BENCHMARK.md or tests/l7-benchmark/ (link-check clean).
• Benchmark numbers / "cheaper than raw" claims fully gone from every doc (not just README).
• Architecture docs (docs/architecture/*) match current reality after this cycle's changes (RESPONSIBILITIES, FLOWS, WORLD_MODEL, ERD, etc.).
• No stale version strings, dead paths, or retired-design "was previously / no longer" commentary.
• docs/ index tables + world-model summaries reflect the moved/retired content.

2. Simplification pass

• Review code/logic touched this cycle for simplification opportunities (hooks, MCP, scripts). Apply low-risk simplifications; file follow-ups for larger ones.

3. DETERMINISM + prompt-grade audit

• Verify all prompts strictly follow docs/prompt-engineering/DETERMINISM.md.
• Every prompt surface (CLAUDE.md, agents/, skills/, commands/, templates/) grades at least A-. Fix anything below.

Acceptance

• bash tests/l1-lint/link-check.sh green; full L1 lint sweep green.
• No stale/contradicted content remains.
• All prompts ≥ A- against DETERMINISM.md.

[ZaxShen]

Hygiene sweep complete on dev (v0.8.4): version literal de-staled + dead lint allowlists removed (PR #617), architecture docs synced to this cycle's behavior (PR #618). Prompt audit: all surfaces >=B, no regressions; sub-A- KEEP-cases tracked in #615. Simplifications deferred to #616. Closing manually (merged to dev).