* refactor(kosong): rename select_tools capability to dynamically_loaded_tools
Rename the `ModelCapability` bit from `select_tools` to `dynamically_loaded_tools` everywhere it is declared, detected, catalogued, and forwarded: kosong `ModelCapability`/catalog, agent-core capability resolution and the `toolSelectEnabled` gate, the SDK catalog-to-alias mapping, and the built-in catalog pruner's keep list.
The old `select_tools` spelling is removed outright rather than kept as an alias — no catalogued model or shipped configuration used the capability, so there is nothing to migrate. Client-side vocabulary (the `select_tools` builtin tool and the `tool-select` experimental flag) is intentionally untouched.
* chore: shorten changeset description
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Co-authored-by: fengchenchen <fengchenchen@moonshot.ai>