feat(checks): distinguish running, pending action, and pending condition states - #179

Update StatusDot STATUS_CONFIG with distinct 'running', 'waiting', and
'pending' styles and tooltips. Expand PullRequestFiltersSchema.checkStatus
and ActionsFiltersSchema.conclusion in view.ts and filterTypes.ts.
Render 'Checks running', 'Pending action', and 'Pending condition'
badges across DependenciesTab, PullRequestsTab, and TrackedTab, and
update checkStatusOrder and repo-group check counts.

Export isWorkflowRunWaiting and isWorkflowRunPending in filters.ts and
surface 'Pending action' and 'Pending condition' across WorkflowRunRow,
WorkflowSummaryCard, ActionsTab (sortWorkflowsByStatus, filteredRuns,
workflowCounts, and collapsedSummary), and DashboardPage custom-tab
action badge counts. Update docs/USER_GUIDE.md and README.md.

Deduplicate the non-terminal waiting/pending icon branch in
WorkflowRunRow and remove a redundant null guard in ActionsTab
sortWorkflowsByStatus. Finalize C4 test additions in ActionsTab.test.tsx
and DashboardPage.test.tsx.

Update the Quick Start hot-poll tip and Tracked Tab PR row description
in docs/USER_GUIDE.md to reflect the 3-way non-terminal check states
(running, Pending action, and Pending condition), deduplicate status
badge JSX in PullRequestsTab and TrackedTab, and include final C4
ActionsTab/DashboardPage test additions.

Cover isWorkflowRunWaiting, isWorkflowRunPending, and
matchesActionsConclusionFilter in tests/lib/filters.test.ts (including
non-terminal exclusion on terminal conclusion filters and action_required
exclusion under conclusion="other") and verify 3-way rollup
classification and partial-error salvage in runForkPRFallback in
tests/services/api.test.ts.

PRs whose checks are "pending" (queued check runs or a pending commit
status) now keep hot-polling for 3 minutes from the first pending
observation on their head commit. This catches runner pickup, gaps
between dependent jobs, and commit-status CI that reports pending while
building, while PRs parked on a condition stop hot-polling after the
window instead of indefinitely.