feat(okr): sync to v1.3.0 from ktg-privat

Syncs all changes from v1.0.0 through v1.3.0:

v1.1 (quick fixes):
- Fix deprecated Viva Goals references
- Add DFO-OKR terminology mapping
- Add tillitsvalgt/fagforening perspective
- Update Objectives recommendation from 3-5 to 2-3

v1.1 (persistent context):
- Deep onboarding interview (full/mvp)
- Persistent .claude/okr/ directory tree
- Context-aware commands
- Cycle archival with retrospective

v1.3 (AI-first differentiators):
- /okr:gap — tildelingsbrev gap analysis with coverage matrix
- /okr:analyse — cross-cycle Mermaid analytics
- SessionStart coaching hook (proactive, phase-aware)
- gapanalytiker + trendanalytiker agents
- inject-okr-context.mjs extended for historikk/

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

plugins/okr/hooks/hooks.json

@@ -1,5 +1,16 @@
 {
   "hooks": {
+    "SessionStart": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "node ${CLAUDE_PLUGIN_ROOT}/hooks/scripts/coaching-hook.mjs",
+            "timeout": 3000
+          }
+        ]
+      }
+    ],
     "UserPromptSubmit": [
       {
         "hooks": [