Add hold-key / auto-repeat key input

[JE-Chen]

Summary

Round-11, automation-core. type_keyboard is an instant down+up — there was no "hold this key for N seconds" (game movement, hold-to-scroll) or "send it at R presses/second" (auto-repeat).

Layers

• Headless core: je_auto_control/utils/key_hold/key_hold.py — plan_key_hold (pure op-plan: press/wait/release, or N spaced key events for rate_hz), hold_key (routes waits to injectable sleep, keys to injectable sink). No PySide6.
• Facade: both re-exported + __all__.
• Executor: AC_hold_key.
• MCP: ac_hold_key (SIDE_EFFECT_ONLY).
• Script Builder: one CommandSpec under Keyboard.

Tests / docs

• test/unit_test/headless/test_key_hold_batch.py — 8 headless tests (hold plan, repeat N events + interval, count clamp, sink/sleep routing, validation + wiring + facade). No real input/waiting.
• EN/Zh feature docs v119_features_doc.rst + toctrees; 3 WHATS_NEW entries.

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[codacy-production]

Not up to standards ⛔

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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