feat: add orch-* orchestrator skill family (#2153)

* feat: add orch-* orchestrator skill family

Lightweight wrappers that orchestrate existing ECC agents through a gated Research -> Plan -> TDD -> Review -> Commit pipeline, right-sized per task.

- orch-pipeline: shared engine (phases, size classifier, two gates, agent map)
- orch-add-feature/change-feature/fix-defect/refine-code/build-mvp: thin wrappers delegating to the engine

* chore: register orch-* family in catalog, command registry, and agent.yaml (post-rebase onto green main)

---------

Co-authored-by: ECC Test <ecc@example.test>

commands/orch-build-mvp.md

@@ -0,0 +1,36 @@
+---
+description: Orchestrate bootstrapping a working MVP from a design/spec doc — ingest, slice, scaffold, TDD, review, gated commit (reuses the GAN harness). Wrapper for the orch-build-mvp skill.
+---
+
+# /orch-build-mvp
+
+Manually launch the **orch-build-mvp** orchestrator: turn an SDD/PRD/system-design
+document into a running vertical slice.
+
+## Usage
+
+```
+/orch-build-mvp <path to design/spec doc>
+```
+
+Examples:
+
+```
+/orch-build-mvp civicpulse/docs/SDD-v0.6.md
+```
+
+## What It Does
+
+Invoke the `orch-build-mvp` skill with `$ARGUMENTS` as the doc path. The skill
+(via the shared `orch-pipeline` engine, full pipeline incl. Scaffold) will:
+
+1. Read the spec; extract scope, locked decisions, and a feature list ordered as
+   **thin vertical slices** (one end-to-end path first). → **GATE 1** (approve slice plan).
+2. Scaffold the first end-to-end slice.
+3. Reuse the GAN harness: translate the SDD into `gan-harness/spec.md` +
+   `eval-rubric.md`, then drive `/gan-build "<brief>" --skip-planner`
+   (generator → evaluator loop) until the score passes or plateaus.
+4. `code-reviewer` (+ `security-reviewer` on any security-trigger slice), then
+   commit the scaffold and each slice as separate `feat:` commits. → **GATE 2**.
+
+If `$ARGUMENTS` is empty, ask the user for the path to the design/spec doc.