v0.12.0 — multi-project by default

v0.12.0 makes Tesserae multi-project by default. The "active project" concept is removed — a smart ask router targets the right project across all registered ones (federated fallback, optional LLM tiebreaker, per-conversation continuity), and bare tesserae serve serves every project under one server with a Projects switcher and per-project live ask. tesserae compile --extractor claude-cli|selective-claude builds the LLM concept/claim layer, hardened so noisy or slow docs never abort a compile (drop unknown edges, per-doc fallback, retry transient generations). Plus Cognee 1.0 compatibility (INSIGHTS→GRAPH_COMPLETION), pip-less uv-tool installs, an interactive tesserae setup, and docs updated throughout.

Full notes: https://github.com/ca1773130n/Tesserae/blob/main/docs/release-notes/v0.12.0.md