Clear Settings dirty state when an integration save succeeds (#2339)

A successful integration save can display “Saved · Connected” before the
parent Settings dialog receives the form's clean state through its
effect. An immediate Escape can therefore be treated as an unsaved-draft
close attempt.

Clear the parent dirty flag in the successful save path, alongside
resetting the saved profile and feedback. This applies to Metrics, Argo
CD and Cost; failed saves still preserve the dirty state. No test sleeps
or timing changes.

Validation: full `make build` (including frontend type-check and
embedding) passed; 27 focused Settings tests passed. Full PR CI passed,
including the complete Settings browser suite. The existing in-flight
Apply/Escape test also passed 20 consecutive local runs against the
rebuilt embedded UI. Visual-test skipped: state propagation only, no
rendered layout change.

Separate from deletion preview/MCP PRs #2050 and #2041; neither branch
is modified.

Author: nadaverell

web/src/components/settings/LocalConnectionSettings.tsx

@@ -398,6 +398,7 @@ export function LocalConnectionSettings({
   const save = async (update: Update) => {
     const data = await fetchConnections(update)
     receive(data)
+    onDirtyChange(false)
     setConfirmBack(false)
     setTask('main')
     setPending(null)