Polish grid loading UX and perf runs

[almogdepaz]

Summary

• soften focused grid chrome while cells are still loading/hydrating/reconnecting
• clarify conflict/displaced terminal labels (take control to view, opened elsewhere)
• add WOLFPACK_PERF_RUNS support plus aggregate perf summary output and per-run session cleanup

Verification

• red/green unit contracts for css loading focus, loading copy, perf run parsing/summary
• bun test tests/unit/terminal-loading-css.test.ts tests/unit/terminal-loading-ui.test.ts tests/unit/terminal-load-perf.test.ts
• bun run typecheck
• WOLFPACK_PERF_RUNS=2 WOLFPACK_PERF_PAGE_LOAD_WAIT_MS=0 WOLFPACK_PERF_GRID_CELLS=2 ... bun run scripts/terminal-load-perf.ts
  • summary.runs = 2
  • grid prewarm hits = 4/4
  • remaining perf-* sessions = 0
• server-only deploy with --broker=no
• browser smoke: focused loading grid cell has subdued border/shadow, loading terminal label, no console errors/failed requests
• bunx playwright test tests/e2e/grid.e2e.ts --project=desktop — 21 passed
• GIT_CONFIG_COUNT=1 GIT_CONFIG_KEY_0=commit.gpgsign GIT_CONFIG_VALUE_0=false bun test — 1818 passed

Note: raw bun test in this local shell hit a 1Password git signing failure in a child test repo; disabling commit signing via env verified the suite.

[almogdepaz]

subagent review: clean. checked PR #189 against main for terminal loading css/copy, perf harness WOLFPACK_PERF_RUNS aggregation/cleanup, generated assets, and attach/reveal timing risk. no correctness/regression findings; no socket/hydration/reveal sequencing changed.