docs(04-01): complete audit-p1-polish-content-script plan

Plan 04-01 closure marker — 04-01-SUMMARY.md + STATE.md position advance
(Plan 1 of 7 -> Plan 2 of 7; Plan 04-02 build hygiene queued NEXT in Wave 1)
+ ROADMAP plan-progress table flip ([ ] -> [x] 04-01-PLAN.md row).

Plan delivered (per SUMMARY):
- Audit P1 #11 fetch URL extraction fix (TWO sites; instanceof Request narrow)
- Audit P1 #14 navigation URL tracking fix (module-level previousUrl)
- Audit P1 #15 rrweb emit timestamp normalization (Date.now() Unix epoch)
- 9 new vitest tests under tests/content/; baseline 171 -> 180/180 GREEN
- tsc-clean preserved; Tier-1 hook-strings inventory unchanged at 12
- Audit P1 polish backlog CLOSED 3/3

Per-task commits (TDD pair):
- 3dbc51c test(04-01): Wave 0 RED — content-script test scaffolds
- 7da30af feat(04-01): Wave 1 GREEN — 3 surgical edits in src/content/index.ts

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.planning/ROADMAP.md

@@ -263,7 +263,7 @@ finalized at plan time):
      live references.
 
 **Plans**: 7 plans (04-01 through 04-07). Wave 1 parallel (04-01 + 04-02) -> Wave 2 sequential (04-03 A29 rewrite -> 04-04 A33 SW persistence -> 04-05 A34 fetch+XHR) -> Wave 5 visual polish (04-06; operator empirical) -> Wave 6 closure (04-07).
-- [ ] 04-01-PLAN.md — Audit P1 polish #11 + #14 + #15 (TDD; 3 unit tests + 3 src/content/index.ts edits)
+- [x] 04-01-PLAN.md — Audit P1 polish #11 + #14 + #15 (TDD; 3 unit tests + 3 src/content/index.ts edits)
 - [ ] 04-02-PLAN.md — Build/CSP hygiene (setimmediate polyfill replacement + dead-code grep + generate-icons.cjs rename)
 - [ ] 04-03-PLAN.md — A29 cs-injection-world rewrite (strict-sentinel filter; closes ~1/3 flake)
 - [ ] 04-04-PLAN.md — A33 SW state persistence (spike-first; 5-min idle + worker.close() CDP; ROADMAP SC #1)