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/tests/test_canned_prompts.py

@@ -0,0 +1,53 @@
+from pathlib import Path
+
+import pytest
+
+import canned_prompts as cp
+
+
+@pytest.fixture()
+def package(tmp_path: Path) -> Path:
+    pkg = tmp_path / "pkg"
+    pkg.mkdir()
+    (pkg / "prompt.yaml").write_text(
+        """\
+format: canned-prompt/v0.1
+id: demo/hello
+name: Hello
+version: 1.0.0
+summary: Say hello.
+template: prompt.md
+inputs:
+  - name: person
+    required: true
+parameters:
+  tone:
+    type: enum
+    values: [warm, formal]
+    default: warm
+""",
+        encoding="utf-8",
+    )
+    (pkg / "prompt.md").write_text(
+        "Say hello to {{ person }} in a {{ tone }} tone.\n", encoding="utf-8"
+    )
+    return pkg
+
+
+def test_validate_and_render(package: Path) -> None:
+    manifest = cp.validate_package(package)
+    values = cp.resolve_values(manifest, {"person": "Ada"})
+    rendered = cp.render_template((package / "prompt.md").read_text(), values)
+    assert rendered == "Say hello to Ada in a warm tone.\n"
+
+
+def test_missing_required_input_fails(package: Path) -> None:
+    manifest = cp.validate_package(package)
+    with pytest.raises(cp.CannedPromptError, match="missing required input"):
+        cp.resolve_values(manifest, {})
+
+
+def test_undeclared_placeholder_fails(package: Path) -> None:
+    (package / "prompt.md").write_text("{{ missing }}\n", encoding="utf-8")
+    with pytest.raises(cp.CannedPromptError, match="undeclared placeholders"):
+        cp.validate_package(package)