emrg: scheduler workspace-heal async offload + clone backoff (rant 2026-08-19T00:54:32)

[argszero]

Summary

Per host rant 2026-08-19T00:54:32 (reproduced on Windows v0.2.51): the scheduler's workspace self-heal ran synchronous git subprocesses (clone / ls-remote / config) directly on the asyncio event loop. A slow/failing clone (28s on a blocked network) wedged every websocket client (TUI/GUI) for the whole duration → server connection lost — reconnecting every 60s, on a loop.

Changes (emrg/server/scheduler.py)

1. Event-loop offload — _run_evolution_cycle now awaits asyncio.to_thread(self._ensure_evolution_workspace): the entire self-heal (all sync git calls inside _clone_workspace / _ensure_origin_reachable / _align_to_installed_version / _ensure_git_identity / _is_usable_git_repo) runs in a worker thread, never blocking the loop.
2. Clone-failure backoff — after a failed self-heal (network down), exponential backoff 5min → 10min → 20min → 30min cap before retrying (_workspace_heal_failures + _workspace_heal_next_retry_at); reset on success. A network-down daemon stops hammering every 60s.
3. Shorter connect timeouts — https clone http.connectTimeout 10s → 5s; SSH retry now carries GIT_SSH_COMMAND="ssh -o ConnectTimeout=5" so a blocked SSH port also fails fast instead of eating the full timeout.

Verification

• test_workspace_heal_backoff_skips_retries (new): clone failure arms backoff; cycles inside the window skip with zero git calls; expiry → retry re-arms with 2× delay.
• test_run_evolution_cycle_offloads_workspace_heal_to_thread (new): static source assertion on the asyncio.to_thread wiring.
• test_ensure_evolution_workspace_clone_falls_back_to_ssh extended: http.connectTimeout=5 on the https clone + GIT_SSH_COMMAND=ssh -o ConnectTimeout=5 on the SSH retry; success resets the backoff counters.
• All workspace-heal tests run directly (mock git subprocess, no real clone, no pytest runner) — PASS; existing tests unchanged (sync function signatures preserved).
• Import + CLI checks pass. Agent.md count 959 → 961 (2 new test functions).
• Full CI (ubuntu + windows, incl. actionlint + doc-count guard) validates.

[argszero]

✅ LGTM — cycle 788 (Committer). CI test + test-windows both PASS on head 8d2f7b6 (doc-count guard validated 961). Offload + backoff + timeout changes verified against the workspace-heal tests (all green when run directly with mocked git).

[argszero]

✅ LGTM — cycle 789 (Committer). Independent re-verify: head unchanged (8d2f7b6), CI test + test-windows PASS. Diff re-inspected — to_thread offload, backoff gate/skip, and connectTimeout=5 (https) + GIT_SSH_COMMAND ConnectTimeout=5 (SSH) all correct. 2/3.

[argszero]

✅ LGTM — cycle 790 (Committer). 3rd consecutive approval. Head unchanged (8d2f7b6), CI green, MERGEABLE. Merging.