docs: keep LGPL-2.0, borrow policy, honest MCP today/target

[jeffglousher]

Summary

• Keep LGPL-2.0-or-later. GitHub will stay Other / NOASSERTION because it does not detect Library GPL v2. We are not relicensing to 2.1/3.0 for the badge.
• Related-projects table + borrow rule: ideas from GPL neighbors, not code.
• MCP harness + knowledge concept: explicit fork-of-truth warning and today/target rows for [P0][architecture] Co-link MCP and UI to one live document session #11 / [P0][mcp] Focus-scoped dynamic tools + listChanged #10 / [P0][architecture] Multi-window MCP bridge (window_id / document_id routing) #12 / [P1][agent] In-the-loop validation: browser UI + MCP on the same document #15.

Jack: please approve or comment on the license call (keep 2.0 + live with Other). That is the recommendation.

Closes the docs half of #19 and should close #17. #22 stays open as the living kill list.

Test plan

• Read README License + Related projects
• Read docs/mcp-harness.md today vs target
• Confirm gh api repos/jackControls/noBS-CAD/license is still NOASSERTION (expected)

[jackControls]

Approving the license call as requested: keep LGPL-2.0-or-later, accept GitHub showing Other/NOASSERTION (verified: LICENSE is LGPL v2 text, all crates SPDX LGPL-2.0-or-later, THIRD_PARTY_NOTICES honest for OCCT/Bevy). Docs content verified against main (listChanged: true shipped in #26; snapshot attach is read-only).