Add doc-approval.recommend WASM agent for pipeline showcase

[enricopiovesan]

Summary

Add the deterministic doc-approval.recommend WASM agent: the final step of
the canonical doc-approval pipeline, analyze → recommend.

Governing Specs

• 069-doc-approval-pipeline-canonicalization
• 058-workflow-pipeline-execution

Input and Output

Input is the existing doc-approval.analyze@1.0.0 output:
{ docType, parties, amounts, confidence, recommendation }.

Output is runtime-owned:
{ recommendation: string, rationale: string, confidence: string }.

Definition of Done

• Contract at contracts/examples/doc-approval/capabilities/recommend/contract.json.
• Deterministic WASM agent at examples/doc-approval/recommend-agent/.
• Component manifest includes the compiled WASM digest.
• doc-approval.pipeline executes analyze then recommend without an extract capability.
• Same analysis input produces identical recommendation output.
• Integration test proves the pipeline and runtime-owned output.

Unblocks

• reference-apps Template executable capability package manifests and deterministic build commands #111 — canonical pipeline workflow
• reference-apps Document adapter responsibilities versus core runtime responsibilities #112 — canonical manifests