Revalidate PR number when opening prompt picker

[PureWeen]

When the user opens the prompt picker, invalidate the PrLinkService cache and re-fetch the current branch's PR. This ensures the autofilled PR context is accurate after branch switches.

Also fixes WsBridgeIntegrationTests build error (ChangeModelAsync signature changed with new reasoningEffort parameter).

Testing: All 3,129 tests pass.

[PureWeen]

🔍 Multi-Model Code Review — PR #506

Revalidate PR number when opening prompt picker

CI Status

⚠️ No CI checks reported on this branch

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Findings

🟡 MODERATE — Popup blocked ~1–2s on every open (3/3 reviewers)

File: PolyPilot/Components/ExpandedSessionView.razor — ShowPromptsPopup (new code ~line 995–1001)

await FetchPrUrlAsync(dir) spawns two subprocesses (git rev-parse + gh pr view, ~1–2s) synchronously in the critical path of ShowPromptsPopup. The popup cannot display until this completes. There is no spinner or disabled state — the user clicks and nothing visibly happens for 1–2s.

The existing pattern in OnParametersSet deliberately uses fire-and-forget (_ = FetchPrUrlAsync(dir)) to avoid this exact latency problem. This PR introduces a regression by blocking.

Suggestion: Use fire-and-forget (_ = FetchPrUrlAsync(dir)) and show the popup immediately with whatever _prLabel is already cached. The popup opens instantly; if the PR number changes, a StateHasChanged() call in the callback will update it.

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🟡 MODERATE — _prLabel not reset when branch has no PR (3/3 reviewers)

File: PolyPilot/Components/ExpandedSessionView.razor — FetchPrUrlAsync method (~line 829–835)

When GetPrUrlForDirectoryAsync returns null (branch has no associated PR), _prUrl is set to null but _prLabel retains its old value (e.g., "#506"). The downstream code in ShowPromptsPopup that injects _prLabel[1..] into the popup JS context has no null-URL guard — so a stale PR number from the previous branch gets autofilled.

Fix: Add else { _prLabel = "PR"; } in FetchPrUrlAsync when _prUrl is null.

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🟢 MINOR — Unconditional cache invalidation defeats caching (3/3 reviewers)

File: PolyPilot/Components/ExpandedSessionView.razor (~line 995)

Invalidate(dir) is called on every prompt picker open, even if the branch hasn't changed since the last check. This completely bypasses the 5-minute TTL cache in PrLinkService, spawning unnecessary subprocesses.

Suggestion: Compare the current branch to a stored value and only invalidate on actual branch change. Or use a shorter TTL check instead of unconditional invalidation.

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✅ No issues — WsBridge test fix (3/3 reviewers)

Named parameter ct: correctly adapts to the new ChangeModelAsync signature with the nullable reasoning effort parameter. Clean, correct fix.

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Re-Review (after d7e9ca21d)

Branch rebased on latest origin/main (1f4f99f7d). Fixes committed as d7e9ca21d.

Previous Finding Status

#	Finding	Status
1	🟡 Popup blocked ~1–2s on every open	✅ FIXED — Changed await FetchPrUrlAsync(dir) to _ = FetchPrUrlAsync(dir) (fire-and-forget). Popup opens instantly with cached _prLabel; background fetch updates via StateHasChanged if PR number changes.
2	🟡 _prLabel not reset when branch has no PR	✅ FIXED — Added else { _prLabel = "PR"; } in FetchPrUrlAsync when _prUrl is null. Stale PR numbers are now cleared.
3	🟢 Unconditional cache invalidation	✅ ADDRESSED — Kept unconditional invalidation (intentional: branch can change without directory changing), but added detailed comment explaining why. Fire-and-forget eliminates the user-visible latency cost.

Test Results

✅ 3,155 tests pass (0 failed, 0 skipped)

Updated Recommendation

✅ Approve — all findings addressed. Popup no longer blocks, stale PR labels cleared, cache invalidation explained.