feat(core): add shared permission flow for tool execution unification (#3723)

* docs: scaffold branch for #3247 tool execution unification

Placeholder commit to establish the branch for PR creation.
Actual refactoring will be done in subsequent commits.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* feat(core): add shared permission flow for tool execution unification

This addresses #3247 by consolidating duplicated tool execution behavior
across Interactive, Non-Interactive, and ACP modes behind shared execution
utilities.

- Add permissionFlow.ts: shared L3→L4 permission evaluation logic
- Add permissionFlow.test.ts: comprehensive test coverage (17 tests)
- Export from index.ts for use across all execution modes

Why: Permission handling logic was duplicated in CoreToolScheduler and
Session.runTool(). This shared module ensures consistent behavior across
all modes and provides a single source of truth for future fixes.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix(e2e): add bundle step to E2E workflow and fix canUseTool test

- Add 'npm run bundle' to E2E workflow so dist/cli.js exists for SDK tests
- Fix 'should handle control responses when stdin closes before replies' test:
  - Use helper.getPath() for absolute file path
  - Make prompt explicitly invoke write_file tool
  - Remove inputStreamDonePromise timeout that caused false failures
  - Add q.endInput() to signal stdin done
  - Assert canUseTool was called and file content is updated

* fix(core): wire evaluatePermissionFlow() and address PR review feedback

Address review feedback on PR #3723:
- Wire evaluatePermissionFlow() in coreToolScheduler.ts (both call sites)
- Wire evaluatePermissionFlow() in Session.ts (ACP mode)
- Delete TOOL_EXECUTION_UNIFICATION.md (had literal \n artifacts)
- Add PermissionFlowPermission union type for stronger typing
- Document the 'default' permission state in docstring
- Use needsConfirmation/isPlanModeBlocked/isAutoEditApproved helpers

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

.github/workflows/e2e.yml

@@ -45,6 +45,10 @@ jobs:
         run: |-
           npm run build
 
+      - name: 'Bundle CLI for E2E tests'
+        run: |-
+          npm run bundle
+
       - name: 'Set up Docker'
         if: |-
           ${{ matrix.sandbox == 'sandbox:docker' }}
@@ -103,6 +107,10 @@ jobs:
         run: |-
           npm run build
 
+      - name: 'Bundle CLI for E2E tests'
+        run: |-
+          npm run bundle
+
       - name: 'Run E2E tests'
         env:
           OPENAI_API_KEY: '${{ secrets.OPENAI_API_KEY }}'