Remove obsolete shell policy helpers

[Aaronontheweb]

Removes compatibility-era shell policy helpers now superseded by the typed path-fact projection.

• Routes legacy reviewed-safe checks through the shared occurrence fact resolver.
• Centralizes ToolAccessDecision conversion.
• Preserves typed and compatibility policy boundaries.
• Removes 101 net production lines.

Validation:

• Release build: 0 warnings and 0 errors
• Full runnable suite: 7,431 passed; 15 expected skips
• Focused policy suite: 563 passed
• Fresh adversarial review: PASS
• Strict OpenSpec, headers, formatting, diff check, and changed-file Slopwatch: PASS