chore(deps): bump typescript from 5.9.3 to 6.0.3 in /agent-service [release/v1.2 backport] (#5869)

### What changes were proposed in this PR?

Backport of #5818 to `release/v1.2`: bump typescript from
5.9.3 to 6.0.3 in /agent-service.

Clean cherry-pick (package.json + bun.lock + LICENSE-binary).

**Risk:** 🔴 **MAJOR** (5→6) compiler; dev/build only.

### Any related issues, documentation, discussions?

Backports #5818 (merged to `main`). No `release/*` label is
added — this PR *is* the backport, and a release label would trigger a
backport-of-a-backport precheck. CI stacks auto-select from the
file-based labels.

### How was this PR tested?

Mirrors the change already merged and CI-validated on `main`
(#5818); verified the backport diff equals the original
bump and applies onto `release/v1.2`. Manual verification:

`tsc`/`bun run build` of agent-service passes under TypeScript 6.

### Was this PR authored or co-authored using generative AI tooling?

Generated-by: Claude Code (Opus 4.8 [1M context])

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: aglinxinyuan

agent-service/LICENSE-binary

@@ -219,7 +219,7 @@ Agent service npm packages:
   - @vercel/oidc@3.0.5
   - ai@5.0.108
   - rxjs@7.8.2
-  - typescript@5.9.3
+  - typescript@6.0.3
 
 --------------------------------------------------------------------------------
 Dependencies under the MIT License

agent-service/bun.lock

@@ -31,7 +31,7 @@
     "pino-pretty": "13.1.3",
     "prettier": "3.8.4",
     "tsx": "4.21.0",
-    "typescript": "5.9.3"
+    "typescript": "6.0.3"
   },
   "packageManager": "yarn@4.5.1+sha512.341db9396b6e289fecc30cd7ab3af65060e05ebff4b3b47547b278b9e67b08f485ecd8c79006b405446262142c7a38154445ef7f17c1d5d1de7d90bf9ce7054d"
 }