Refresh visible reviews automatically and stop settled merged polling (#25788)

Refresh only actual on-screen review cards and the selected visible review panel, with a single metadata owner per execution host. Open reviews refresh every 60 seconds when selected and 120 seconds otherwise. Settled merged reviews stop automatic refresh; pending merged checks continue, hidden rows stop, and work changes or stale re-exposure discover fresh state.

Remove the polling setting. Preserve provider/SSH/runtime ownership, mixed-version cache behavior, failure backoff, bounded foreground admission, request coalescing, and mutation invalidation. Cover older persisted caches and unknown HEADs.

Validated with 1,628 focused tests, typechecking, lint/code-quality gates, hidden Electron viewport checks, and parallel Codex/Claude Opus 5.5 adversarial reviews. Measurements and policy details are in PR #25788.

Fixes #25746

Co-authored-by: ggbdpq <ggbdpq@gmail.com>

src/main/github/github-read-execution-scope.ts

@@ -0,0 +1,19 @@
+import { createHash } from 'node:crypto'
+import type { GitHubRepoExecOptions } from './github-api-repository'
+
+export function githubReadExecutionScope(
+  options: GitHubRepoExecOptions,
+  environment: NodeJS.ProcessEnv = options.env ?? process.env
+): string {
+  const { admissionTier: _admissionTier, ...executionOptions } = options
+  // gh wrappers and credential selection can depend on cwd and the inherited environment.
+  return createHash('sha256')
+    .update(
+      JSON.stringify([
+        executionOptions,
+        process.cwd(),
+        Object.entries(environment).sort(([a], [b]) => a.localeCompare(b))
+      ])
+    )
+    .digest('hex')
+}