feat: refine v0.12.0 release surface

Author: Nefza99

CHANGELOG.md

@@ -0,0 +1,31 @@
+# Changelog
+
+All notable changes to Rebis will be documented here.
+
+## v0.12.0
+
+This release is the cleanest public prototype of Rebis so far. It does not reinvent the runtime. It refines the public surface around the existing runtime spine so engineers can understand, run, and evaluate it more quickly.
+
+### Added
+
+- `docs/INDEX.md` as a canonical docs entrypoint
+- `CHANGELOG.md` and `RELEASE_NOTES.md`
+- canonical demo commands:
+  - `npm run demo:single-agent`
+  - `npm run demo:council`
+- stronger example output formatting for the single-agent and council clients
+
+### Changed
+
+- refined README around a runtime-first public story
+- clarified implemented runtime modules vs conceptual architecture targets
+- tightened release/install documentation
+- standardized terminology around governance runtime, transition governance, structured handoffs, task-state fidelity, and minimal repair
+- bumped runtime/package version surface to `0.12.0`
+
+### Kept Intentionally
+
+- the current runtime spine
+- the current Windows shell + installer path
+- deterministic evaluation/benchmark surfaces
+- the experimental but runnable council/convergence runtime