docs(browser): document six browser tools and enablement gates

docs/plans/state.json

@@ -3,6 +3,21 @@
   "updated_at": "2026-02-17",
   "description": "Tracks the status of all Flynn plans and implementation phases",
   "plans": {
+    "browser-tools-activation-clarity": {
+      "status": "completed",
+      "date": "2026-02-17",
+      "updated": "2026-02-17",
+      "summary": "Clarified browser automation availability and activation path: documented the full six browser tools (`browser.navigate`, `browser.screenshot`, `browser.click`, `browser.type`, `browser.content`, `browser.eval`), added default config guidance for enabling browser support, added startup diagnostics when browser tools are disabled or blocked by tool policy, and added config schema coverage for browser defaults/overrides.",
+      "files_modified": [
+        "src/daemon/tools.ts",
+        "src/config/schema.test.ts",
+        "config/default.yaml",
+        "README.md",
+        "docs/api/TOOLS.md",
+        "docs/plans/state.json"
+      ],
+      "test_status": "pnpm test:run src/config/schema.test.ts + pnpm typecheck passing"
+    },
     "automation-daily-briefing-and-cron-backup-scheduling": {
       "status": "completed",
       "date": "2026-02-16",
@@ -3548,7 +3563,7 @@
     }
   },
   "overall_progress": {
-    "total_test_count": 1874,
+    "total_test_count": 1876,
     "all_tests_passing": true,
     "p0_completion": "3/3 (100%)",
     "p1_completion": "4/4 (100%)",