fix: inline validation report template and schema with @ inclusion

Small structural files (<150 lines) that the skill cannot function
without should use @ inclusion per AGENTS.md skill compliance checklist,
ensuring the model always has the report contract in context.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: rodrigohaertel-ctrl

plugins/compound-engineering/skills/ce-prototype/SKILL.md

@@ -169,15 +169,17 @@ For each goal, record:
 
 ### Phase 3: Write Validation Report
 
-Read `assets/validation-report-template.md` for the report structure.
+Use the template and schema below to write the validation report.
 
 Write the report to `docs/prototypes/<topic-slug>-validation-<date>.md`. If a report with the same name already exists (e.g., multiple prototype rounds on the same day), append the next available sequence number: `-002`, `-003`, etc.
 
 Create `docs/prototypes/` if it does not exist.
 
 The validation report is the durable output — it survives after the prototype code is deleted. It must contain enough detail that `/ce:plan` (or a future reader) can understand what was tested and what was learned without access to the prototype code.
 
-For detailed field descriptions and frontmatter schema, see `references/validation-report-schema.md`.
+@./assets/validation-report-template.md
+
+@./references/validation-report-schema.md
 
 ### Phase 4: Clean Up and Recommend