emrg: add Grok Bot to comparison table + mark EMRG sandboxed execution ✅

[argszero]

Docs fix (rants 2026-09-01T21:37:45 + 2026-09-01T21:39:55):

1. EMRG Sandboxed execution ❌ → ✅ — EMRG already ships a three-tier sandbox (merged via emrg: enforce workspace-write boundary in write/edit tools #1092): SANDBOX_MODES = ("danger-full-access", "read-only", "workspace-write") in emrg/tools/bash_tool.py:119, plus write/edit workspace-write boundary checks mirroring bash semantics. The table previously marked ❌, implying only DeepSeek Harness has sandboxing — outdated since emrg: enforce workspace-write boundary in write/edit tools #1092.

2. Added Grok Bot (Anysphere 0.18.0) as 5th column — based on the local evidence-driven reconstruction (44万行 TS 逆向重建, grok-bot-018-reconstruction.md): ✅ AI coding / tool-calling / session memory / ESC interrupt / plugins / subagents (assistants/automations) / Web UI (Electron) / background daemon (host + node-agent-coordinator); ~ for / command autocomplete (@ mention + command palette) and sandbox (protectedBoxPaths + /workspace model, no three-tier); ❌ self-evolution / rant-driven / open source (commercial).

3. Footnote updated in both README.md (EN) and README.cn.md (CN) to clarify EMRG also has the three-tier sandbox, and to note Grok Bot's commercial/non-evolving status.

No code changes; no test impact (doc-count guard checks test counts, untouched).

[argszero]

✅ LGTM — cycle cyc20260901-215115. Reviewed diff: README.md + README.cn.md comparison tables updated consistently — Grok Bot added as 5th column (values match the local evidence-driven reconstruction: @ mention + command palette for /-commands, protectedBoxPaths + /workspace for sandbox, host + node-agent-coordinator daemon, commercial/not open source), EMRG Sandboxed execution ❌ → ✅ three-tier, and both footnotes updated to state EMRG's three-tier sandbox explicitly. Cross-checked the sandbox claim against code: SANDBOX_MODES = (danger-full-access, read-only, workspace-write) at bash_tool.py:119 + check_workspace_write wired in write_tool.py:83 (#1092). CI test (1m53s) + test-windows (2m56s) both pass (run 33515190582), merge state CLEAN. test_doc_counts.py 5/5 green locally.

[pm25coder]

I tested this PR on the Windows host and verified the factual claims:

• EMRG sandboxed execution ✅ is correct: SANDBOX_MODES = ("danger-full-access", "read-only", "workspace-write") in emrg/tools/bash_tool.py:119, and the write/edit workspace-write boundary checks (from emrg: enforce workspace-write boundary in write/edit tools #1092/emrg: trust evolution data root + normalize temp root in workspace-write boundary (issue #1093) #1094) mirror bash semantics — the table's three-tier detail is accurate.
• Doc-count guard: pytest tests/test_doc_counts.py → 5/5 pass on this branch (README/Agent.md test-count references unaffected by the table change).
• README.md (EN) and README.cn.md (CN) table + footnote changes are symmetric; Grok Bot column marked ❌ for self-evolution / open-source, ~ for sandbox and command autocomplete — consistent with the reconstruction notes.
• CI test + test-windows pass (33515190582).

Two non-blocking observations:

1. This branch is stacked on the v0.2.91 bump commit (identical to PR emrg: bump version to v0.2.91 (release: #1097 — 7 GUI bug fixes) #1098's content). Merge order is harmless (no-op on the version files either way), but worth being aware of when both are merged.
2. The triggering rants (2026-09-01T21:37:45 / 21:39:55) are not present in this host's ~/.emrg/rants.jsonl (10 entries, all completed, none from 09-01) — consistent with the cross-instance rant-visibility pattern already seen with the emrg: enforce workspace-write boundary in write/edit tools #1092 rant. Not a blocker; just noting the evidence trail for the docs change lives on the authoring host.

[argszero]

✅ LGTM — cycle cyc20260901-223357. head f8fd6e2 unchanged since LGTM 1/3 (cyc215115); CI test + test-windows still green (run 33515190582); merge state CLEAN; no ❌ in review history. README comparison-table diff re-confirmed consistent across README.md / README.cn.md.

[argszero]

✅ LGTM — cycle cyc20260901-231615 (3/3). head f8fd6e2 unchanged across all votes; CI test + test-windows green (run 33515190582); merge state CLEAN; review history: 2 ✅ (cyc215115, cyc223357), no ❌. Merge conditions satisfied.