cleanup(config): remove literal credential compatibility residue

Adapter schemas now carry only credential references, but the Models join, onboarding readiness, shipped overlays, SDK scaffolding, fixtures, and active decision prose still treated a redacted literal apiKey as a supported compatibility state. That residue made an unsupported field look contractual and pinned Schemastery silent-dropping as behavior.

Delete those branches and examples, and let compositions and scaffolds use adapter-owned reference and environment resolution. Do not add a tombstone validator or change generic unknown-key behavior: literal adapter credentials have no migration contract to preserve.

examples/acp-agent/tests/fs-search.cordis.yml

@@ -2,8 +2,6 @@
 - id: llm-deepseek
   name: '@deepseek-ai/dsh-llm-deepseek'
   config:
-    apiKey: !!js process.env.DEEPSEEK_API_KEY
-    baseURL: !!js process.env.DEEPSEEK_BASE_URL
     models:
       - id: deepseek-v4-pro
 

examples/acp-agent/tests/pwsh.cordis.yml

@@ -2,8 +2,6 @@
 - id: llm-deepseek
   name: '@deepseek-ai/dsh-llm-deepseek'
   config:
-    apiKey: !!js process.env.DEEPSEEK_API_KEY
-    baseURL: !!js process.env.DEEPSEEK_BASE_URL
     models:
       - id: deepseek-v4-pro