feat(app): find text throughout chat history

Discover candidate transcript locations on the daemon, then reuse prompt navigation to load history and verify rendered occurrences on the client. Keep search state inside its own modules without changing timeline or task presentation contracts.

package-lock.json

@@ -39002,6 +39002,7 @@
         "express": "^4.18.2",
         "fast-deep-equal": "^3.1.3",
         "lru-cache": "^11.5.1",
+        "markdown-it": "^10.0.0",
         "mnemonic-id": "^3.2.7",
         "node-pty": "1.2.0-beta.15",
         "openai": "^6.44.0",
@@ -39024,6 +39025,7 @@
       "devDependencies": {
         "@playwright/test": "^1.56.1",
         "@types/express": "^4.17.20",
+        "@types/markdown-it": "^14.2.0",
         "@types/node": "^20.9.0",
         "@types/qrcode": "^1.5.6",
         "@types/uuid": "^9.0.7",
@@ -39468,6 +39470,17 @@
         "cross-spawn": "7.0.6"
       }
     },
+    "packages/server/node_modules/@types/markdown-it": {
+      "version": "14.2.0",
+      "resolved": "https://registry.npmjs.org/@types/markdown-it/-/markdown-it-14.2.0.tgz",
+      "integrity": "sha512-NoQ2yGlLWj4wpxMs+TYmRKk3thDrQ97agr7sFqfLsAlvoS8SNQuTrlObhFqG9iugdTtgOE9jpJ6FNM4ZGsa5xQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/linkify-it": "^5",
+        "@types/mdurl": "^2"
+      }
+    },
     "packages/server/node_modules/@vitest/expect": {
       "version": "4.1.6",
       "resolved": "https://registry.npmjs.org/@vitest/expect/-/expect-4.1.6.tgz",