DatabaseTool: enforce param validation and query timeouts; add tests

[Psyborgs-git]

Motivation

• Harden the database tool to prevent malformed or slow queries from reaching the DB execution path by validating inputs and bounding execution time.
• Fail fast and provide clearer errors when callers submit invalid params or omit required parameter bindings for named SQL tokens.

Description

• Added asyncio-based timeouts around SQL execution using the existing _QUERY_TIMEOUT_S to ensure queries cannot run indefinitely (_query_read and _query_write).
• Enforced that params must be a mapping by returning an explicit error when params is not a dict for read/write operations.
• Added detection of named parameter tokens (:name) and return a clear error when SQL contains named tokens but no params payload is provided.
• Introduced _PARAM_TOKEN_RE and small input/validation checks and wiring to existing confirmation flow for write operations, and added a focused test module tests/test_db_tool.py covering the new checks and a parameterized read against an in-memory SQLite engine.

Testing

• Successfully type-checked the modified files with python -m py_compile harness/tools/db_tool.py tests/test_db_tool.py and no syntax errors were reported.
• Ran pytest -q tests/test_db_tool.py tests/test_terminal_tool.py in this environment but the run failed due to missing test runtime dependency pytest_asyncio (ModuleNotFoundError: No module named 'pytest_asyncio').
• The new tests/test_db_tool.py includes assertions for invalid params type handling, missing named-parameter payloads for writes, and a successful bound-parameter query_read against an in-memory SQLite DB (intended to pass when pytest_asyncio is available).

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Codex Task