Project home: system spec, working notes, and setup

Gives the system specification an owner. It defines the PR-nnn project
requirements and SR-nnn cross-component contracts that every component spec
traces up to, and until now it lived in no repository at all.

The three component repositories are linked from the README and gitignored
here rather than added as submodules. A submodule pins a commit, so with
feature branches and worktrees in flight across the components, every
component commit would leave this repository's pointer stale. The dependency
is meant to run the other way: components pull this repository in for the
shared tooling and system spec, both of which change rarely.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,20 @@
+# Component repositories. They are separate repos with their own remotes; this
+# README explains how to clone them. They are deliberately NOT submodules —
+# see "Why not submodules for the components" in README.md.
+/jRay/
+/scene-actor-extraction/
+/JRay-public-server/
+
+# Python artefacts from the traceability tooling
+__pycache__/
+*.pyc
+
+# Generated traceability output — regenerate with the gate, never hand-edit.
+traces-report.json
+
+# Editor / OS noise
+.vscode/
+.idea/
+*.swp
+*~
+.DS_Store