fix: remove render-phase React hazards

[Harry19081]

Problem

Several React Compiler diagnostics were suppressing real render-phase hazards: Tooltip mutated a ref-backed holder during render, GitStatusProvider synchronized live refs during render, TeamRuntimePanel read wall-clock time during render, and Source Control used a render-mutated ref cache. Valid clone/ref forwarding, virtualizer, TanStack, and server-rendered test-probe suppressions also lacked enough context to distinguish false positives from bugs.

Solution

• Compose Tooltip child refs in React callback-ref commits and ignore transient detach/reattach nulls for positioning, with a regression test for changing callback refs.
• Synchronize Git WebSocket freshness refs in a layout effect, retaining one listener lifecycle instead of resubscribing on status writes.
• Replace TeamRuntimePanel render-time Date.now reads with a minute-aligned, visibility-aware recursive timeout that pauses hidden and cleans up on unmount.
• Replace the Source Control render-time ref cache with a complete primitive working-tree identity snapshot; unchanged status pings retain the derived array, while real path/status/staged/rename changes invalidate it.
• Add precise reasons to intentional React Compiler suppressions for cloneElement ref forwarding, ref-capturing factories, TanStack imperative APIs, and test-only server-render probes.

Potential risks

Tooltip ref identity changes still follow React callback-ref semantics, but positioning state now ignores only the transient null and updates for a genuinely different DOM node. The runtime clock adds at most one timeout while the panel is mounted and visible; it removes the timer while hidden and during cleanup. The Source Control identity path serializes the same O(n) fields previously derived and compared on every status ping, and only parses/re-derives when the primitive key changes.

Verification

• Changed-file ESLint with --report-unused-disable-directives: passed
• pnpm typecheck: passed
• Focused Vitest: 5 files, 31 tests passed
• git diff --check: passed
• Repository pre-commit gates: lint-staged, TypeScript, and staged-file checks passed

Performance verdict: lifecycle-safe and expected neutral-to-improved. No hidden-page timer remains, Git listener ownership/count is unchanged, Tooltip removes render-phase ref mutation without adding a subscription, and unchanged git-status pings no longer allocate a derived GitFile list before equality comparison.