feat(monitoring): unify deployment outcomes and notification settings

[Hydralerne]

Superseded by combined PR #1148. This branch is preserved in the combined history. The complete migration sequence and review fixes are included there; all 15 combined CI checks pass. Merge #1148 instead of this individual draft.

Monitoring now includes deployment outcomes and a shared notification editor. Deployment totals cover the entire selected UTC window independently of pagination and status drill-down; bookmarked /deployments URLs retain their filters at the new location.

Settings, Monitoring and mail administration reuse the same channel editor. Channel readiness distinguishes enabled and verified states; delivery-history read failures have a retry and never send or acknowledge a notification. Account, organization and instance changes reset private state. Inbox acknowledgement also preserves pending delivery leases and the first seen timestamp.

Dependency

Targets feat/cloud-build-admission-recovered. Its inherited Actions and Cloud code is excluded from this PR's diff. Review and merge the Cloud prerequisite into #1116 first, then merge this branch into that same updated branch. This keeps the shared history repository and locale additions from conflicting or being republished.

Validation

• Full combined bun run test --continue=always: 11 workspace suites passed, including 8,912 API tests. The combined stack was checked against current main.

• 114 dashboard tests and 35 API/database/platform tests passed, including channel editing, one-time secrets, scope changes, delivery acknowledgement, history aggregates and redirects.

• API and dashboard TypeScript checks passed.

• Public SDK/CLI build and documentation examples passed.

• The complete recovered stack merges cleanly with current main. New source/tests formatted; failure boundaries observed.

Recovered through a separate snapshot and branch; the original development worktree is preserved. Kept draft while the stacked prerequisites are reviewed.