feat(bridges): add QQ bot bridge with group + C2C support

[tsint]

Adds QQ Bot bridge support through the official qq-botpy SDK.

Changes

• Add /qq command for configuring, starting, stopping, and checking QQ bridge status.
• Support QQ group and C2C private chat messages.
• Route QQ messages into the existing agent query flow with per-target job queues.
• Stream agent output and tool progress back to QQ.
• Support QQ permission/input prompts, scoped to the original QQ target to prevent cross-chat approvals.
• Support QQ image attachments by forwarding downloaded images into the agent turn.
• Add QQ runtime context fields and bridge turn detection.
• Add optional qq dependency extra using qq-botpy.
• Update prompt golden fixture for the new /qq command.
• Add QQ bridge unit tests covering config, routing, reply context, queueing, streaming hook serialization, image handling, and permission target isolation.

Testing

• uv run python -m pytest tests/e2e_prompt_regression.py tests/test_prompt_selection.py tests/test_prompt_assembly.py tests/test_qq_bridge.py -q
• uv run python -m py_compile bridges/qq.py runtime.py tools/interaction.py tests/test_qq_bridge.py

$ uv run python -m pytest tests/e2e_prompt_regression.py tests/test_prompt_selection.py tests/test_prompt_assembly.py tests/test_qq_bridge.py -q
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97 passed in 1.86s
$ uv run python -m py_compile bridges/qq.py runtime.py tools/interaction.py tests/test_qq_bridge.py
$ 

[chauncygu]

@copilot resolve the merge conflicts in this pull request