feat(skills): validate manifest installer specs

docs/plans/state.json

@@ -1333,9 +1333,22 @@
       },
       "phase_3_installer_specs": {
         "priority": "P1",
-        "status": "not_started",
+        "status": "in_progress",
         "description": "Auto-install dependencies (brew/node/go/download) with package manager detection",
-        "effort": "3-4 hours"
+        "effort": "3-4 hours",
+        "sub_slices": {
+          "manifest_installers_type_validation": {
+            "status": "completed",
+            "description": "Added manifest installers type definitions and loader validation for brew/node/go/download installer specs with focused tests",
+            "files_modified": [
+              "src/skills/types.ts",
+              "src/skills/index.ts",
+              "src/skills/loader.ts",
+              "src/skills/loader.test.ts"
+            ],
+            "test_status": "pnpm typecheck + pnpm test:run src/skills/loader.test.ts + pnpm test:run + pnpm lint (warnings only, 0 errors) + pnpm build passing"
+          }
+        }
       }
     }
   },
@@ -1362,7 +1375,7 @@
   },
 
   "overall_progress": {
-    "total_test_count": 1517,
+    "total_test_count": 1520,
     "all_tests_passing": true,
     "p0_completion": "3/3 (100%)",
     "p1_completion": "4/4 (100%)",
@@ -1382,7 +1395,7 @@
     "gmail_auth_cli": "flynn gmail-auth command implemented with OAuth2 flow, doctor check, config routed to Telegram",
     "native_audio_support": "completed — smart routing for native audio (Gemini/OpenAI/GitHub) vs Whisper transcription fallback",
     "remaining_phases_completion": "Phase 1: 3/3 (100%) — context levels, command registry, memory structure. Phase 2: 2/2 (100%) — component registry, confidence routing. Phase 3: 2/2 (100%) — adaptive memory/compaction, truthfulness/autonomy hardening",
-    "next_up": "Skills infrastructure Phase 3: installer specs kickoff (manifest installers type support with validation and tests)"
+    "next_up": "Skills infrastructure Phase 3: add installer execution planning surface (selection rules and dry-run installer plan output)"
   },
   "soul_md_and_cron_create": {
     "date": "2026-02-11",