PAIDEIA MCP v0.5.0

Initial standalone PAIDEIA MCP release for Alt local models.\n\nHighlights:\n- Local stdio MCP server with 22 tools and 5 prompt templates.\n- PAIDEIA repo parser/action composer for the canonical 16 PAIDEIA actions.\n- Safe local course-folder writers for markdown artifacts, course indexes, grade reports, errors, weakmaps, and Exam Radar imports.\n- Alt local stdio setup example and MCP smoke-test script.\n\nVerified with:\n- python3 -m pytest -q: 37 passed\n- python3 scripts/smoke_stdio.py: tool/prompt discovery and init_course call successful