Implement Tier 1 detections from existing data (#9, #11, #13, #15, #19,
#23, #35) and Tier 2 detections from event history scanning (#8, #12,
#26, #27, #28, #29, #30). Adds detectEventHistoryErrors with single-pass
scanning and updates getApplicableCommonErrors to accept optional event
history. All 35 error definitions now have active detection logic.

* Add common-error component with 35 workflow configuration warnings (#3262)

Create a reusable common-error component system for displaying operational
guidance about workflow misconfigurations. Includes typed data for 35 known
issues with severity levels, documentation links, and a /common-errors route.

* Integrate common-error detection into workflow detail header

Add automatic detection of 21 workflow configuration issues and display
them as warnings in the workflow header. Detection covers timeout
misconfigurations, retry policy issues, heartbeat settings, and more.
Also fixes raw code references in error titles.

* Fix detection accuracy for common errors

- Raise #31 threshold from 4000 to 10000 to match "significant additional events"
- Add null guards to all getCommonErrorById calls via addError helper
- Detect #3 (short timeout) from workflowRunTimeout on first event, not just execution timeout
- Fix #10 false positives for empty retry policy objects
- Handle protobuf nanos field in durationToSeconds for sub-second durations

* Add detection logic for 14 remaining common errors (#8-#35)

Implement Tier 1 detections from existing data (#9, #11, #13, #15, #19,
#23, #35) and Tier 2 detections from event history scanning (#8, #12,
#26, #27, #28, #29, #30). Adds detectEventHistoryErrors with single-pass
scanning and updates getApplicableCommonErrors to accept optional event
history. All 35 error definitions now have active detection logic.

* Add snippet to pass in headerSnippet for common errors. Refactor workflow-run-layout to svelte5

* Add back common errors page

* Remove common errors from snippet

* Revert alert to current styles

* Fix test failures for detectFirstEventErrors and routeForCommonErrors

Update detectFirstEventErrors test calls to match updated function
signature that removed the workflow parameter. Add missing
routeForCommonErrors test case to route-for-base-path tests.

* Replace VerticalNav with tab group on common errors page

Switch from VerticalNav sidebar to TabButtons for severity filtering.
Remove layout reset (@) since the page no longer needs a custom layout.
Add WorkflowCommonErrors snippet to workflow run layout.

* Remove common errors from header snippet

* Fix type errors in alert component and stories

Rename $$Props to Props in alert.svelte for Svelte 5 convention.
Update stories to use module script and ComponentProps for proper
type inference with Storybook.

* Update src/lib/components/common-errors/common-error.svelte

Co-authored-by: Laura Whitaker <[email protected]>

* Update src/lib/components/common-errors/common-errors-data.ts

Co-authored-by: Laura Whitaker <[email protected]>

* Update src/lib/utilities/common-error-detection.ts

Co-authored-by: Laura Whitaker <[email protected]>

* Remove workflow-common-errors.svelte

* Remove getCommonErrorsByCategory

* Update src/lib/components/common-errors/common-error-list.svelte

Co-authored-by: Laura Whitaker <[email protected]>

* Fix naming

* Add back workflow-common-errors.svelte
;5u

* Formatting

* Add type predicate filter

---------

Co-authored-by: Laura Whitaker <[email protected]>

- activity-options-update-drawer: default backoffCoefficient to 2 (server
  default) instead of 0 — Temporal rejects < 1, and the full field mask
  always submits it. (finding 2)
- getFirstWholeNumberUnit: add overloads so passing a defaultUnit returns
  a non-undefined label; narrow initialTimeoutUnit to DefaultUnits and drop
  4 now-dead `?? 'second(s)'` fallbacks. (finding 4)
- dangerfile: match changed files by normalized path equality instead of
  fragile bidirectional substring (missed regressions / false-blocked
  suffix collisions). (finding 5)
- timeline-graph-row: guard divide-by-zero so an undefined workflowDistance
  yields 0, not Infinity, as an SVG coordinate. (finding 7)
- rename MostRecentWOrkflowVersionStamp -> MostRecentWorkflowVersionStamp
  typo (now load-bearing imported surface). (finding 9)

Deferred: #3 (requestFromAPI -> Promise<T|undefined> is a 128-call-site
refactor, its own PR), #6 (documented zod input/output boundary), #8
(pre-existing on main, not this change).