emrg: fix rant UX (daemon-authoritative timestamp + GUI dialog textarea + UTF-8 emrgd.log) + locale-safe tests

[pm25coder]

Fixes three issues found on a UTC+8 Windows host (Chinese locale), plus a test-only locale bug.

[argszero]

✅ LGTM — cycle 20260807-222237 (1st angle: correctness + locale-safety)

Reviewed head 444e514 (fetched and tested locally):

• daemon-authoritative timestamp: daemon.py now stamps datetime.now().astimezone().isoformat() (tz-aware local), ignoring client-supplied timestamps. Fixes the real bug: GUI sent new Date().toISOString() (UTC Z, 8h behind on UTC+8 hosts), TUI sent naive local time — inconsistent and mis-sorted. Tz-aware local ISO sorts correctly and is self-describing. test_rant_field_order asserts the client-supplied stale UTC value (…Z) is ignored, entry is tz-aware, not Z-suffixed, and within 60s of wall clock — discriminating.
• main.js: timestamp deliberately not sent; comment documents the rationale. TUI client (app.py) still sends its own timestamp but daemon now ignores it — single source of truth, no behavior break.
• main.py: RotatingFileHandler gains encoding="utf-8" — fixes GBK code-page mojibake of CJK log lines on zh-CN Windows.
• components.css: .dialog-card label > textarea matches the rant-dialog markup (index.html rant-message textarea is inside label) — full width, min-height 120px, vertical resize, inherited font. The tiny default textarea is fixed.
• tests: read_text(encoding="utf-8") in test_config/test_memory — locale-safe on Windows (GBK default locale would fail otherwise).
• Validation: 572 Python + 93 GUI tests pass locally on this branch; CI test workflow green (31187043479).
• Note: package-lock.json churn (0.2.0→0.2.11 version + peer-flag reshuffle) is npm noise from version sync — harmless, consistent with the 0.2.11 bump.

[argszero]

✅ LGTM — cycle 20260807-222539 (2nd angle: test discriminative power + tz edge cases)

Verified on head 444e514:

• Positive: test_rant_field_order passes (tz-aware local, stale UTC ignored, within 60s).
• Negative (per #455 lesson, ran it): reverted daemon to msg.get("timestamp", datetime.now().isoformat()) (old behavior) → the test FAILS because the stale client UTC Z value leaks through the endswith("Z") / tzinfo asserts. Restored → passes. Genuinely discriminating across all three regression modes: client-timestamp leak (Z suffix), naive local (tzinfo None), naive UTC (Z suffix).
• Tz edge cases: fromisoformat handles the +08:00 offset; now(ts.tzinfo) normalizes comparison; DST-transition hosts still within 60s (wall clock comparison, not epoch). Solid.
• Full 572 Python + 93 GUI pass on this branch; CI green (31187043479).

[argszero]

✅ LGTM — cycle 20260807-222827 (3rd/final angle: end-to-end Windows zh-CN behavior + hygiene)

Verified on head 444e514:

• End-to-end: GUI rant flow no longer sends timestamp → daemon stamps tz-aware local (+08:00 on zh-CN host). TUI still sends its own naive-local timestamp but the daemon IGNORES it (verified in daemon.py: entry timestamp comes only from datetime.now().astimezone()) — single source of truth, no client breakage. Sorting in rants.jsonl is now correct across both clients on any timezone.
• zh-CN Windows runtime: RotatingFileHandler encoding='utf-8' → CJK log lines no longer GBK-mojibake; read_text(encoding='utf-8') in tests → locale-safe. textarea CSS selector matches the actual rant-dialog markup (.dialog-card label > textarea — rant-message is directly inside label).
• package-lock.json: version 0.2.0→0.2.11 sync (correct, matches package.json) + peer-flag reshuffle is npm regenerated noise — harmless, no dependency version changes.
• Validation: 572 Python + 93 GUI tests pass locally on this branch; CI test workflow green (31187043479).
• Three consecutive ✅ from distinct cycles (222237 correctness, 222539 discriminative power, this cycle e2e/hygiene), no ❌. Ready to merge.