[Molecule-Platform-Evolvement-Manager]
Closes the first item from #2071 (Canvas test gaps follow-up):
adds behavioural coverage for the shared template-deploy hook that
both TemplatePalette (sidebar) and EmptyState (welcome grid) drive.
10 cases across 4 buckets:
**Happy path (4):**
- preflight ok → POST /workspaces → onDeployed fires with new id
- caller-supplied canvasCoords flows into the POST body
- default coords fall in [100,500) × [100,400) when canvasCoords omitted
- template.runtime is preferred over the resolveRuntime fallback
(locks the deduped-fallback table contract added in #2061)
**Preflight failures (2):**
- network throw sets error AND clears `deploying` (regression test
for the "stranded button" bug called out in the SUT's inline
comment — drop the try block and you'll fail this test)
- not-ok-with-missing-keys opens the modal without firing POST
**Modal lifecycle (2):**
- 'keys added' click retries POST without re-running preflight
(verifies the executeDeploy / deploy split — preflight call count
stays at 1, POST count goes to 1)
- 'cancel' click closes modal without firing POST
**POST failures (2):**
- Error rejection surfaces the message
- non-Error rejection surfaces the "Deploy failed" fallback
Mocks `@/lib/api`, `@/lib/deploy-preflight`, and `@/components/MissingKeysModal`
(stand-in component exposes the two callbacks as test-id buttons —
the real radix modal is irrelevant to this hook's behavior). Test
file follows the `vi.hoisted` + import-after-mocks pattern from
`canvas/src/app/__tests__/orgs-page.test.tsx`.
## Test plan
- [x] All 10 cases pass locally (`vitest run useTemplateDeploy.test.tsx`)
- [x] No changes to the SUT — pure additive coverage
- [ ] CI green
Follow-ups for the rest of #2071 (separate PRs):
- A2AEdge rendering + click-to-select-source
- OrgCancelButton cancel flow + optimistic state
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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