v0.6.0

• Upstream sync: bump pin fd8794b → 7557f9e (upstream v0.6.0); reviewed all 17 commits, including the new src/retrieval/ and src/linking/ modules. Provider streaming (#932), visualizer URL decoding (#917), installer runtime, upstream wiki updates, and release chores remain out of scope.
• Port repository retrieval and linked-workspace Q&A (#905): optional openwiki_search/openwiki_read, explicit ambiguous-workspace selection, exact section reads with wiki identity, and local Markdown fallback; update the managed AGENTS.md snippet to use retrieval only when needed. The MCP server, ranking engine, and workspace registry remain upstream-owned.
• Port the personal-mode shell boundary (d3e5f21) through generation, Q&A, source wiring, and scheduled-run guidance: read-only source tools replace CLI/Git/shell ingestion, connector-relative paths replace host raw-file reads, and native file snapshots/clock tools replace shell bookkeeping. Also remove two stale annotations that contradicted the existing every-run metadata refresh rule.
• Adopt upstream's exact legacy OpenWiki-section migration (#914), preserving fenced examples and user-edited lines, removing duplicate legacy sections before marker validation, and retaining import-only CLAUDE.md files after migration.
• Document native parallel-worker semantics (#903) while retaining upstream's sequential host-agent contract; add omp and antigravity provenance actors (#893/#922), and generated-PR notices in both GitHub Actions examples (#911).