Support Python 3.11 and pin mcp to 1.x; release 0.3.0

[zarubaf]

Summary

Lowers the minimum Python from 3.12 to 3.11, fixes a latent packaging bug with the mcp dependency, and bumps to 0.3.0.

Python 3.11 backport

No source changes were needed. Every tracked .py file already parses under ast.parse(feature_version=(3,11)) — no PEP 695 type params, no PEP 701 f-strings, no itertools.batched / typing.override.

The only real blocker was Cargo.toml: pyo3's abi3-py312 feature sets the minimum CPython the stable-ABI wheel will load on. Lowering it to abi3-py311 is purely a floor change — we still ship one cp311-abi3 wheel per platform, and it still runs on 3.12/3.13/3.14.

mcp 2.x fix

mcp>=1.0.0 was unconstrained. mcp 2.x renamed mcp.server.fastmcp.FastMCP to mcp.server.mcpserver.MCPServer, so a fresh pip install tsunami-wave resolved to 2.x and python/tsunami/server.py died on import:

ModuleNotFoundError: No module named 'mcp.server.fastmcp'. This is mcp 2.x,
where FastMCP was renamed to MCPServer...

uv.lock pinned 1.26.0, so this never hit CI or local dev — only end users installing from PyPI. Now constrained to mcp>=1.0.0,<2.

CI

The test job pinned no Python version at all, so the new lower bound would have rotted silently. It now runs a ["3.11", "3.14"] matrix.

Verification

	3.11.15	3.14.0
pytest tests/	58 passed	58 passed
import tsunami.server	OK	OK
tsunami info on arbiter FST	OK	OK
resolved mcp	1.26.0	1.26.0

maturin develop produces tsunami_wave-0.3.0-cp311-abi3-*.whl. cargo check --locked --workspace is clean and tsunami-serve still builds and runs, so the Rust MCP server release path is unaffected.

Version bump

pyproject.toml plus all three workspace crates (tsunami, tsunami-core, tsunami-serve) go to 0.3.0, with Cargo.lock and uv.lock refreshed to match.

🤖 Generated with Claude Code

https://claude.ai/code/session_0192r9HCCGprJJNyx2sow4kL