Adopt stage-1 capability cut and product capability model

Persist capability/feature vocabulary, v0 model, and founder stage-1 must set
(onboarding, spaces/pages with Title/Abstract/Visual, page copy and transfer).
Mark CSOC-WP-0001-T03 done; add CSOC-WP-0006 for implementation.

docs/capability/vocabulary.md

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+# Capability / feature vocabulary (coulomb-social)
+
+Status: **adopted for product work** (2026-08-12)  
+Promote to fleet canon after one full cutover cycle.  
+Cites: orthogonal architecture Capability (C1–C3, `realizes`); reuse-surface
+for *cross-product* reuse only — not product feature flags.
+
+## The coin
+
+| Side | Name | Question |
+|------|------|----------|
+| **Utility** | **Capability** | What can a person *do* or *get*? Stable job-to-be-done. |
+| **Implementation** | **Feature** | Which concrete product slice delivers (part of) that utility? |
+
+Capabilities change slowly. Features appear, split, toggle, and retire under them.
+
+## Hierarchy (depth capped)
+
+```text
+Capability
+  └── Feature+          (implementation slices)
+        └── Realization (code, config, deploy)   — optional detail
+        └── Toggle?     (runtime/config switch on a feature or stage)
+```
+
+Rules:
+
+1. **Capabilities: few.** Target ~10–30 for all of coulomb.social, not hundreds.
+2. **No unlimited trees.** At most capability → optional sub-capability → feature.
+3. **One feature, one primary capability.** Cross-links allowed as `supports`, not multi-parent ownership.
+4. **Toggles attach to features (or release stages), never to capabilities.**  
+   “Turn off identity” is a product decision, not a flag.
+5. **Feature cut = prioritize capabilities**, then name which features are enough to call a capability *realized for that stage*.
+6. **Partial rebuild is valid.** Stage N can retire Bubble as *productive* home while Bubble remains *reference-only* for later capabilities.
+
+## Status labels
+
+### Capability priority (cut / roadmap)
+
+| Label | Meaning |
+|-------|---------|
+| `must_stage_1` | Required before user transfer + Bubble productive retirement |
+| `later` | Rebuild after stage 1; not a transfer blocker |
+| `out` | Explicitly not rebuilding (or only if strategy changes) |
+| `platform` | Delivered by platform dependency (NetKingdom, Forgejo, …) |
+
+### Feature implementation status
+
+| Label | Meaning |
+|-------|---------|
+| `shipped` | On app.coulomb.social (or ready to enable) |
+| `partial` | Exists but missing stage-1 acceptance bits |
+| `todo` | Not built; required for its capability stage |
+| `later` | Intentionally after stage 1 |
+| `blocked` | Waiting on external dependency |
+
+## What not to conflate
+
+| Concept | Home |
+|---------|------|
+| Product capability (user utility) | This model |
+| Fleet reusable capability | reuse-surface registry |
+| Platform service (OIDC, Forgejo, apps-pg) | Platform deps; product *depends_on* |
+| Feature toggle | Env/settings/flag on a **feature** |
+| Workplan task | Execution unit; may implement many features |
+
+## Naming
+
+- Capabilities: `cap.<kebab>` — noun phrase of utility  
+  e.g. `cap.space-content`
+- Features: `feat.<kebab>` — verb/noun of implementation  
+  e.g. `feat.space-md-render`
+- Prefer stable ids; titles may change.