CANP-WP-0002 T04: eval schema, render checks and output criteria

`evals/` was a reserved path holding unvalidated blobs: section 12 named the
directory and gave an illustrative snippet, but nothing was specified, so no
tool could act on an eval file.

Every eval file must now declare a `schema`, and CPF defines exactly one —
`canned-prompts/eval-rubric/v0.1`. Unrecognized schemas stay legal and are
skipped rather than rejected, so the format gains something actionable without
becoming an evaluation language, which remains a non-goal.

The schema splits along the same seam as T01 and T03. Render checks
(`contains`, `not_contains`, `resolves_all`) assert properties of the rendered
prompt text, need no model, and are therefore run by the reference CLI. Output
criteria describe a good result and are declared but not run, because judging
them requires a model. That division is now the format's consistent answer to
"deterministic locally, or not".

An eval references a fixture already declared in the manifest's `examples`
rather than carrying its own copy, so an example that is also an eval fixture
stays honest — both break together.

An eval declares assessment and must not record outcomes. Results are run
evidence and live outside the immutable package, per INTENT.md and section 17.

Spec: 12 rewritten with 12.1, 18 (rules 17-18), 21 (`eval` verb).

Reference CLI: read_eval, validate_eval, load_example_values,
run_render_checks, cmd_eval; a failed render check exits non-zero.
Tests 42 -> 51.

examples/pqrst-estimate/evals/quality.yaml is a real eval with four render
checks and four output criteria, and it passes.

Fixes a latent bug reaching a fixture exposed: coerce_value assumed every
value was a command-line string, so a YAML fixture carrying a real type
(include_rationale: true) crashed on .lower(). Typed values are now validated
but not re-parsed.

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

CannedPromptFormat-v0.1.md

@@ -678,20 +678,73 @@ Tools MAY render examples directly.
 
 `evals` is a list of relative paths to evaluation specifications.
 
-CPF v0.1 deliberately does not standardize a universal evaluation language. Eval files SHOULD therefore declare their own evaluator or schema.
+CPF does not standardize a universal evaluation language, which remains a
+non-goal. Every eval file MUST declare a `schema`, and a consumer MUST ignore a
+schema it does not recognize rather than guessing at its meaning.
 
-Example:
+CPF defines exactly one schema, so that `evals/` holds something tools can act
+on rather than opaque blobs. Other schemas remain legal and are simply not
+interpreted here.
+
+### 12.1 `canned-prompts/eval-rubric/v0.1`
 
 ```yaml
 schema: canned-prompts/eval-rubric/v0.1
-name: code-review-quality
-criteria:
-  - identifies correctness risks
-  - distinguishes blocking from advisory findings
-  - avoids inventing repository facts
+name: pqrst-estimate-quality
+description: The estimate reads as a post-session audit, not a plan.
+example: examples/basic.yaml
+
+render:
+  - contains: "must sum to exactly 100%"
+  - not_contains: "{{"
+  - resolves_all: true
+
+output:
+  criteria:
+    - Percentages sum to exactly 100%.
+    - Categories are not silently renamed or merged.
+    - Rationale cites evidence from the session summary.
 ```
 
-A registry may associate externally collected run/eval evidence with `<id>@<version>` without mutating the package.
+| Field | Required | Meaning |
+|---|---:|---|
+| `schema` | yes | MUST be `canned-prompts/eval-rubric/v0.1` |
+| `name` | yes | Identifies this eval within the package |
+| `description` | no | What the eval is for |
+| `example` | no | Fixture to run against; MUST be a path declared in the manifest's `examples` |
+| `render` | no | Deterministic checks on the **rendered prompt** |
+| `output` | no | Model-judged criteria for the **result** |
+
+An eval declaring neither `render` nor `output` asserts nothing and SHOULD be
+rejected.
+
+#### Render checks
+
+Render checks assert properties of the rendered prompt text. They need no
+model, so **any implementation that can render can run them.**
+
+| Check | Passes when |
+|---|---|
+| `contains: <text>` | the rendered prompt contains that text |
+| `not_contains: <text>` | it does not |
+| `resolves_all: true` | every placeholder resolved to a value |
+
+Each entry is a single-key mapping, so a check may appear more than once.
+
+#### Output criteria
+
+`output.criteria` is a list of statements about a good result. Judging them
+requires running the prompt and assessing what comes back, which CPF does not
+specify and most consumers cannot do. They are **declared, not run** — the
+same division as `include` and `derive` in § 10.2, and for the same reason.
+
+#### Results are not part of the package
+
+An eval file declares what to assess; it MUST NOT record outcomes. Results are
+run evidence, which lives outside the immutable package (§ 17) and may be
+associated with `<id>@<version>` by a registry or evaluation system without
+mutating it. A tool reporting results SHOULD identify the package version, the
+eval `name`, and each check's outcome.
 
 ## 13. Provenance and lineage
 
@@ -786,7 +839,12 @@ A v0.1 validator SHOULD verify at least:
 15. every dependency referenced by a composition or derived default declares a
     `version`, and that version is a semver literal, `any`, `newest`, or a
     `>=` lower bound (§ 10.1);
-16. inclusion does not form a cycle.
+16. inclusion does not form a cycle;
+17. every eval file parses and declares a `schema`;
+18. an eval declaring `canned-prompts/eval-rubric/v0.1` has a `name`, asserts
+    something via `render` or `output`, uses only known render checks, and —
+    when it declares an `example` — names a path listed in the manifest's
+    `examples`.
 
 A validator SHOULD additionally warn when a package intended for publication
 declares an inline derivation prompt (§ 6.1).
@@ -960,6 +1018,13 @@ The reference tool satisfies `include` defaults, because inclusion is
 deterministic and needs no model, and reports `derive` defaults it cannot
 satisfy.
 
+```text
+eval ID        run an installed package's render checks
+```
+
+`eval` runs the deterministic render checks of every recognized eval file and
+reports output criteria as declared but not run.
+
 The reference tool never calls a model, so its `resolve` handles supplied
 values and static defaults only and reports any input whose derived default it
 cannot satisfy. `render` performs the same resolution and then substitutes;