Tool runtime scheduler key becomes unavailable after HMR reload

[zhang-guo-wen]

Runtime failure

In the Web development profile, rebuilding packages while the app is running can cause the next tool call to fail with:

Cannot read properties of undefined (reading 'prepare')

The failing access is in packages/core/agent-loop/src/tool-calls.ts:

ctx.tools[TOOL_RUNTIME_SCHEDULER].prepare(call.exec)

Cause

ToolRuntime can survive an HMR/module reload while packages/core/tools/src/index.ts is re-evaluated. TOOL_RUNTIME_SCHEDULER currently uses Symbol(...), so the reloaded consumer gets a different symbol identity and cannot find the scheduler installed under the previous key.

Local fix

export const TOOL_RUNTIME_SCHEDULER: unique symbol = Symbol.for('@deepseek-ai/dsh-tools.scheduler')

I also added a regression assertion:

expect(Symbol.keyFor(TOOL_RUNTIME_SCHEDULER)).toBe('@deepseek-ai/dsh-tools.scheduler')

Validation completed locally:

• focused packages/core/tools Vitest test passes
• pnpm exec tsc -b packages/core/tools packages/core/agent-loop --pretty false passes
• the already running Web profile recovers through HMR after the rebuilt bundle loads

The original Symbol(...) declaration is present in commit a2d0f7f.

[zhang-guo-wen]

This is the HMR-triggered form of the same symbol-identity failure reported in #7011. I added the Windows reproduction, Symbol.for(...) fix, and validation details there so follow-up can stay in one discussion.