fix(core): preserve admitted tool names

[kitlangton]

What

Keep provider-advertised direct tool names identical to the canonical names admitted by the tool registry.

Before / After

Before: src/tool.ts normalized and validated a registration such as namespace slack.admin plus tool name send.message, then stored it under slack_admin_send_message. tool/runtime.ts independently recomputed the provider definition name from the producer object. If that object changed after registration, the provider could receive a name the registry lookup never admitted, so executing the advertised call returned Unknown tool.

After: provider definitions receive the already-admitted registry key. Advertisement, permission fallback, registration storage, and execution lookup now use the same canonical identity even if the producer object's name changes after registration.

flowchart LR
  subgraph before["Before: duplicated recomputation"]
    B0["Producer tool object"] --> B1["Registry normalizes and admits"]
    B0 --> B2["Runtime recomputes name"]
    B1 --> B3["Execution lookup key"]
    B2 --> B4["Provider definition name"]
    B4 -. "may not match" .-> B3
  end

  subgraph after["After: one admitted identity"]
    A0["Producer tool object"] --> A1["Registry normalizes and admits"]
    A1 --> A2["Admitted registry key"]
    A2 --> A3["Provider definition name"]
    A2 --> A4["Execution lookup key"]
  end

Loading

How

• packages/core/src/tool/runtime.ts makes definition accept its canonical name explicitly and removes its duplicate normalization implementation.
• packages/core/src/tool.ts passes direct registration map keys into definition derivation and uses the canonical synthetic name execute for CodeMode.
• packages/core/src/codemode/tool.ts passes each existing admitted registration key while deriving child schemas; CodeMode still owns its separate catalog path representation.
• packages/core/test/tool-schema.test.ts updates direct definition call sites for the explicit identity.
• packages/core/test/session-runner-tool-registry.test.ts proves a namespaced, normalized tool advertises and executes through its admitted lookup key after the producer object's name is mutated.

Passing the admitted identity is preferable to sharing a normalization helper because a shared helper would still rederive identity from a producer object after validation. The registration key is already the authoritative result of normalization, collision validation, permission fallback, and map admission, so passing it removes both drift and a second derivation point without reversing the registry/runtime dependency direction.

Scope

• Does not change normalization or namespace rules.
• Does not change CodeMode catalog paths or tool execution behavior.
• Does not add registration cloning or immutability enforcement.
• Does not change Protocol or Server HTTP APIs.

Production change: 5 insertions, 12 deletions (-7 net) across packages/core/src.

Testing

• cd packages/core && bun run test test/tool-schema.test.ts test/session-runner-tool-registry.test.ts test/codemode.test.ts (31 passed)
• cd packages/core && bun typecheck
• Push hook: bun turbo typecheck --concurrency=3 (33/33 tasks successful)
• bun run lint packages/core/src/tool.ts packages/core/src/tool/runtime.ts packages/core/src/codemode/tool.ts packages/core/test/tool-schema.test.ts packages/core/test/session-runner-tool-registry.test.ts (0 errors; 17 warnings on pre-existing lines)
• git diff --check
• Scoped Prettier was run on the five changed files. Its whole-file rewrites on four already-unformatted files were reverted to avoid unrelated churn; bunx prettier --check ... continues to report that pre-existing formatting drift.