Register with Custodian State Hub and seed format open-questions workplan

Register canned-prompts under agents / practice (topic
c1d199b6-55ee-4db6-b49e-257a9f0f15ac, workplan prefix CANP-WP) via
`statehub register`, then replace the generated placeholders with
repo-specific facts.

- SCOPE.md: real boundaries drawn from INTENT.md's deliberate boundary,
  current state (spec v0.1 + reference CLI, 3/3 tests pass, example
  round-trips), and the developer workflow.
- AGENTS.md: drop the unresolved {CREDENTIAL_ROUTING} template token left
  by the generator.
- CANP-WP-0001: bootstrap tasks closed.
- CANP-WP-0002: new workplan carrying the five § 23 open questions promoted
  from "experience will decide" to "decide for v0.2" — optional-input
  defaults (static or derived), registry namespaces/ownership, prompt
  composition, canonical eval schemas, typed context/dependency contracts —
  plus two reference-implementation conformance defects found in review
  (prerelease versions sort as newest; copy_immutable packages the whole
  source directory).

Also lands the previously untracked seed: INTENT.md, the CPF v0.1 spec,
the reference CLI, and examples/pqrst-estimate.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Bjefh8NUiEiahN4JLwoSKM

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 388925@bnt-lap001
Assistant-Session: 3507023f-e0fd-4a1e-9d90-a0d4217d1502

reference/README.md

@@ -0,0 +1,49 @@
+# canned-prompts reference CLI
+
+This is intentionally a **small reference implementation**, not the intended final architecture.
+
+It demonstrates six verbs:
+
+```text
+add      PATH
+search   QUERY
+show     ID
+render   ID --set key=value
+install  ID [--version VERSION]
+publish  PATH
+```
+
+The implementation uses a local catalog plus a filesystem registry and performs no model calls.
+
+## Stores
+
+Default locations:
+
+```text
+~/.canned-prompts/catalog
+~/.canned-prompts/registry
+```
+
+Catalog and registry both store packages as:
+
+```text
+<store>/<id path>/<version>/...
+```
+
+For example:
+
+```text
+~/.canned-prompts/catalog/practice/pqrst-estimate/0.1.0/
+```
+
+## Design choices
+
+- YAML manifest via PyYAML.
+- `{{ name }}` template substitution only.
+- No arbitrary expression/code execution.
+- Published versions are immutable by default.
+- `install` copies from registry to catalog.
+- `add` copies a package directly to catalog.
+- `search`, `show`, and `render` operate on catalog packages.
+
+Use this implementation to challenge the format. Replace it once real usage reveals the right architecture.