Add read-only MCP server for Droid ASC

[NonMirror]

Droid ASC can now be used directly by MCP clients such as Codex over stdio, exposing class decompilation, class listing, manifest decoding, and cross-DEX reference search without launching a separate CLI process for each request.

The server returns structured results with timing, counts, and truncation metadata, validates paths and query parameters, marks all tools read-only, and caches repeated class/manifest queries using file metadata. This also adds the droidasc-mcp console entry point, MCP SDK dependency, Codex registration instructions, and MCP protocol tests.

Validation:

• python tests/run_tests.py --require-decompiler — 69 tests passed.
• python -m compileall -q droidasc tests/test_mcp_server.py and git diff --check passed.
• Installed droidasc-mcp with python -m pip install -e . and verified stdio initialization/tool discovery with the official MCP client.
• Verified a real stdio list_classes call against a generated DEX fixture.
• Verified temporary Codex CLI registration via codex mcp add/get; the registration was removed afterward. A full model-driven codex exec attempt launched the server but did not complete because that session stalled during unrelated existing MCP/model initialization, so no end-to-end Codex model success is claimed.

[MG1937]

Sorry, but at the moment we are not planning to integrate MCP or skills. ASC is currently provided as a minimal suite containing only core functionality, available for all third parties to use freely. Adding MCP could restrict the freedom of other projects that integrate DroidASC into their pipelines.