docs(02): capture phase context — discuss-phase complete

Phase 2 (Stabilize export pipeline) discuss-phase landed via inline canonical
workflow execution. 02-CONTEXT.md captures 3 locked decisions:

- **D-P2-01:** Offscreen-minted Blob URL pipeline replaces base64 data: URL
  download path (src/background/index.ts:709-710). SW Blob → offscreen
  URL.createObjectURL → SW chrome.downloads.download → URL.revokeObjectURL on
  onChanged. Closes audit P0-6. Unblocks real-archive size (>2 MB).

- **D-P2-02:** meta.json schema migrates singular `url: string` to plural
  `urls: string[]` capturing all tabs visible during the 30s recording window.
  Schema-breaking change requires REQUIREMENTS.md REQ-meta-json-schema
  amendment + SessionMetadata type update. Closes audit P1 #10 captured-URL bug.

- **D-P2-03:** Full Phase 2 scope = Blob URL migration + meta.urls schema
  migration + strict meta.json schema validation test + UAT harness A24+
  <5s latency assertion. ~3-4 plans expected.

Decision provenance:
- D-P2-01 rationale: user "up to you. If you think we need to migrate — good
  let's do it." Plus analysis: real archives EXCEED base64 cap.
- D-P2-02 rationale: user picked "All tabs' URLs as an array
  (meta.json.urls)" — highest informational fidelity for multi-tab bug
  reproduction. Privacy acceptable per "log is internal" v1 charter.
- D-P2-03 rationale: user picked "Full scope: bug fixes + schema + harness
  latency assertion".

Canonical references + code context + deferred items captured in CONTEXT.md.
Phase boundary explicit: not from-scratch; closes residual gaps after Plans
01-08/01-09/01-10/01-12 substantively shipped REQ-popup-ui + REQ-archive-
layout + REQ-screenshot-on-export.

Next: /gsd-plan-phase 2.

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

.planning/STATE.md

@@ -3,8 +3,8 @@ gsd_state_version: 1.0
 milestone: v2.0.0
 milestone_name: milestone
 status: executing
-stopped_at: Phase 1 FULLY CLOSED 2026-05-20. Roadmap RE-PHASED 2026-05-20 per charter shift — original Phase 2 (DOM/event-capture privacy) REMOVED; DOM/event-log verification absorbed by new Phase 3 (SPEC §10 smoke); REQ-password-confidentiality moved to Out of Scope (v1) per "we don't care about privacy hardening. At least here." Total phases now 4. Phase 2 (export pipeline) discussion next.
-last_updated: "2026-05-20T14:30:00.000Z"
+stopped_at: Phase 2 (Stabilize export pipeline) discuss-phase complete 2026-05-20. 02-CONTEXT.md captures 3 locked decisions — D-P2-01 offscreen-minted Blob URL pipeline (closes P0-6); D-P2-02 meta.json schema migrates url→urls[]; D-P2-03 full scope ~3-4 plans. Next: /gsd-plan-phase 2.
+last_updated: "2026-05-20T15:00:00.000Z"
 last_activity: 2026-05-20
 progress:
   total_phases: 4