Use --allow-run=bash in CI + specify in AGENTS.md

The new chpwd-hook integration test spawns a bash subprocess to drive
the generated shellcode end-to-end, so --allow-run` is required.
This change also updates AGENTS.md's documented test command to match
the change in ci.yml.

Scoped to bash so the test suite cannot spawn arbitrary executables.

Author: gaggle

.github/workflows/ci.yml

@@ -40,4 +40,4 @@ jobs:
       - uses: denolib/setup-deno@v2
         with:
           deno-version: v2.x
-      - run: deno test --allow-read --allow-write --allow-env
+      - run: deno test --allow-read --allow-write --allow-env --allow-run=bash

AGENTS.md

@@ -7,7 +7,7 @@ Public repository for developer environment activation tooling.
 - `deno fmt --check .`
 - `deno lint .`
 - `deno check ./app.ts`
-- `deno test --allow-read --allow-write --allow-env`
+- `deno test --allow-read --allow-write --allow-env --allow-run=bash`
 
 ## Always Do