#21642: fix(ui): disable dashboard session delete for webchat clients

## Summary - Problem: Dashboard Sessions showed a `Delete` button, but Dashboard connections are webchat clients and `sessions.delete` is rejected server-side. - Why it matters: Users are presented with an action that always fails, creating confusion and noisy error banners. - What changed: Sessions view now treats delete as unavailable in Dashboard mode, shows an informational callout, and disables row-level Delete buttons with a clear reason. - What did NOT change (scope boundary): No gateway/server behavior changes; only Dashboard UI behavior and tests were updated. ## Change Type (select all) - [x] Bug fix - [ ] Feature - [ ] Refactor - [ ] Docs - [ ] Security hardening - [ ] Chore/infra ## Scope (select all touched areas) - [ ] Gateway / orchestration - [ ] Skills / tool execution - [ ] Auth / tokens - [ ] Memory / storage - [ ] Integrations - [ ] API / contracts - [x] UI / DX - [ ] CI/CD / infra ## Linked Issue/PR - Closes #21264 - Related #21264 ## User-visible / Behavior Changes - Dashboard Sessions now shows delete as unavailable with an info callout. - Delete buttons are disabled in Dashboard sessions with a clear reason. ## Security Impact (required) - New permissions/capabilities? (`No`) - Secrets/tokens handling changed? (`No`) - New/changed network calls? (`No`) - Command/tool execution surface changed? (`No`) - Data access scope changed? (`No`) - If any `Yes`, explain risk + mitigation: ## Repro + Verification ### Environment - OS: macOS (reporter), local dev machine - Runtime/container: node + control-ui - Model/provider: N/A - Integration/channel (if any): Dashboard webchat client - Relevant config (redacted): default Dashboard connection mode ### Steps 1. Open Dashboard and navigate to Sessions. 2. Observe a session row and click `Delete`. 3. See request fail with `webchat clients cannot delete sessions`. ### Expected - Delete is not offered as an actionable control in Dashboard webchat context, or is disabled with clear guidance. ### Actual - Delete was displayed as actionable but always failed with an API error. ## Issues List | ID | Issue | Status | Notes | | --- | --- | --- | --- | | PR-21642-BUG-01 | Dashboard sessions exposed `Delete` for webchat clients even though `sessions.delete` is rejected | Fixed | Delete is disabled and an info callout explains why | ## Fix Approach - Added `canDeleteSessions` and `deleteUnavailableReason` props to the sessions view. - Rendered an info callout when delete is unavailable. - Disabled Delete actions per row when unavailable. - Wired app render state to pass Dashboard-specific delete capability (`false`). - Added a sessions view test for the disabled-delete/notice behavior. ## Testing Results - ✅ `pnpm --dir ui exec vitest run --config vitest.config.ts src/ui/views/sessions.test.ts src/ui/controllers/sessions.test.ts` - ✅ `pnpm --dir ui build` - ⚠️ `pnpm --dir ui test -- src/ui/views/sessions.test.ts` (runs broader UI suite in this environment and reports unrelated pre-existing failures outside this change) ## Evidence - [x] Failing test/log before + passing after - [ ] Trace/log snippets - [ ] Screenshot/recording - [ ] Perf numbers (if relevant) ## Human Verification (required) - Verified scenarios: sessions view renders delete-unavailable callout; delete button is disabled with reason tooltip. - Edge cases checked: existing sessions view tests for custom values still pass. - What you did **not** verify: full interactive Dashboard manual flow against a running gateway instance. ## Compatibility / Migration - Backward compatible? (`Yes`) - Config/env changes? (`No`) - Migration needed? (`No`) - If yes, exact upgrade steps: ## Failure Recovery (if this breaks) - How to disable/revert this change quickly: revert this PR commit. - Files/config to restore: `ui/src/ui/views/sessions.ts`, `ui/src/ui/app-render.ts`, `ui/src/ui/views/sessions.test.ts`. - Known bad symptoms reviewers should watch for: Delete appearing enabled in Dashboard Sessions. ## Risks and Mitigations - Risk: Users may still expect delete directly in Dashboard. - Mitigation: UI now explicitly explains unavailability in-context. <!-- greptile_comment --> <h3>Greptile Summary</h3> This PR correctly addresses the issue where Dashboard sessions displayed a Delete button that always failed for webchat clients. The implementation adds `canDeleteSessions` and `deleteUnavailableReason` props to properly disable the delete functionality and display an informational callout explaining why deletion is unavailable. **Key changes:** - Added new props to `SessionsProps` type for controlling delete availability - Modified `renderSessions` to show an info callout when delete is unavailable - Updated `renderRow` to disable delete buttons with a tooltip explanation - Hardcoded `canDeleteSessions: false` in `app-render.ts` for Dashboard context - Added test coverage for the disabled-delete scenario The implementation is sound because the Dashboard UI always operates in webchat mode (confirmed at `app-gateway.ts:142`), where session deletion is correctly rejected server-side. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk - The changes are well-contained to the UI layer with no gateway/server modifications. The implementation correctly addresses the stated problem by disabling delete functionality in Dashboard sessions where it's server-rejected. Test coverage validates the new behavior, and the changes are backward compatible with no breaking changes to existing functionality. - No files require special attention _{Last reviewed commit: a005f32} <!-- greptile_other_comments_section --> <!-- /greptile_comment -->