v0.8.7 — MCP --tag scope fix

Fixes

• mcp: --tag is no longer silently bypassed by the graph and passage tiers. The graph tools (graph_query, text_search, graph_neighbors) and the --document-index tier read the whole database, so combining them with --tag exposed concepts outside the tag scope. grafito-mcp now rejects --tag together with --enable-graph or --document-index, and build_tools raises ValueError for the same combination. Docs and --help state that those tiers are not tag-scoped. (#18)
• ci: publish workflow now supports metadata 2.5 and manual runs.