Isolate Base-specific IDE and history policy from generic base_cli

[codeforester]

Context

The original review still finds two Base-specific policies embedded in the generic package:

• lib/python/base_cli/ide_schema.py hard-codes VS Code/Cursor configuration details.
• _BASE_DISPLAY_COMMANDS in lib/python/base_cli/history.py hard-codes Base command-display policy.

These should not silently become part of the reusable base-cli contract.

Scope

• Decide where the Base integration owns IDE schema and history display policy.
• Move or inject those policies without breaking supported Base behavior.
• Preserve or explicitly deprecate any public imports before removal.
• Add focused tests for the generic package and the Base integration boundary.

This is a design and follow-up implementation item; it is intentionally separate from the mechanical regression fixes in the current review train.

[codeforester]

Implementation is ready in draft PR #18: #18. The coordinated Base consumer changes are in draft basefoundry/base#1822 and should merge after #18. Both repositories' test suites are green.