docs(08-01): complete diff viewer plan

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.planning/STATE.md

@@ -3,14 +3,14 @@ gsd_state_version: 1.0
 milestone: v9.6
 milestone_name: milestone
 status: completed
-stopped_at: Completed 07-01-PLAN.md
-last_updated: "2026-03-13T04:14:00.000Z"
+stopped_at: Completed 08-01-PLAN.md
+last_updated: "2026-03-13T04:21:58.035Z"
 last_activity: 2026-03-13 -- Completed 07-01 config history UI timeline component
 progress:
   total_phases: 10
   completed_phases: 7
-  total_plans: 10
-  completed_plans: 10
+  total_plans: 12
+  completed_plans: 11
   percent: 100
 ---
 
@@ -21,16 +21,16 @@ progress:
 See: .planning/PROJECT.md (updated 2026-03-12)
 
 **Core value:** Operators can see exactly what changed on a router and when, with reliable config snapshots for download
-**Current focus:** Phase 7: Config History UI
+**Current focus:** Phase 8: Diff Viewer & Download
 
 ## Current Position
 
-Phase: 7 of 10 (Config History UI) -- COMPLETE
-Plan: 1 of 1 in current phase (all complete)
-Status: Phase 7 complete
-Last activity: 2026-03-13 -- Completed 07-01 config history UI timeline component
+Phase: 8 of 10 (Diff Viewer & Download)
+Plan: 1 of 2 in current phase
+Status: Plan 08-01 complete
+Last activity: 2026-03-13 -- Completed 08-01 diff viewer component
 
-Progress: [██████████] 100%
+Progress: [█████████░] 92%
 
 ## Performance Metrics
 
@@ -58,6 +58,7 @@ Progress: [██████████] 100%
 | Phase 06 P01 | 2min | 2 tasks | 4 files |
 | Phase 06 P02 | 2min | 2 tasks | 3 files |
 | Phase 07 P01 | 3min | 2 tasks | 3 files |
+| Phase 08 P01 | 1min | 2 tasks | 3 files |
 
 ## Accumulated Context
 
@@ -89,6 +90,8 @@ Recent decisions affecting current work:
 - [Phase 06]: 500 error wrapping for Transit decrypt failures in router layer, not service
 - [Phase 07]: Reimplemented formatRelativeTime locally in ConfigHistorySection (matches BackupTimeline pattern)
 - [Phase 07]: 60s refetchInterval polling for near-real-time config change visibility
+- [Phase 08]: DiffViewer rendered inline above timeline (not modal) for context preservation
+- [Phase 08]: Line classification function for unified diff: +green, -red, @@blue, ---/+++ muted
 
 ### Pending Todos
 
@@ -100,6 +103,6 @@ None yet.
 
 ## Session Continuity
 
-Last session: 2026-03-13T04:14:00.000Z
-Stopped at: Completed 07-01-PLAN.md
+Last session: 2026-03-13T04:21:58.032Z
+Stopped at: Completed 08-01-PLAN.md
 Resume file: None