docs(plans): reconcile plan statuses; archive 10 done plans

Move ten completed plans from plans/ to plans/done/ and update the index:
- 2026-07-18 session-review-three-sessions, 2026-07-20 desktop-mascot,
  2026-07-20 session-review-ten-sessions, 2026-07-21 chat-full-polish,
  2026-07-29 health-check-reality-and-knowledge-graph,
  2026-07-30 session-review-plan-drift, and the four 2026-08-03 chat plans
  (changes-review, reliability-and-ux-audit, cyberspace-style-adoption,
  working-visibility).
- Refresh two stale statuses: cyberspace-style-adoption ("Draft" -> shipped as
  full replacement in v0.16.0/757ef2f) and health-check-reality ("ready for
  implementation" -> shipped across the v0.14.x-0.16.x check commits).
- .gitignore: ignore local tooling artifacts (.playwright-mcp/, config-screen.png).

No code change. index.md Active/Done tables now match the filesystem (no orphans).

VERSION: 0.17.0 -> 0.17.1

.gitignore

@@ -24,3 +24,7 @@ cmd/desktop/build/
 cmd/desktop/Oikos
 desktop
 /eval
+
+# Local tooling artifacts (Playwright MCP session logs, stray screenshots)
+.playwright-mcp/
+config-screen.png