fix(build): order prompts after its compiled workspace dependencies

Root verification can compile @elizaos/prompts while @elizaos/common is rebuilding its declarations. Prompts imports compiled common helpers, but its Turbo build override declares no prerequisites. Observed failure: TS7016 for @elizaos/common in src/rendering.ts during concurrent root verify; common DTS output completed in the same run.

Use the existing workspace dependency graph for the prompts build instead of an empty override. Verify by moving both generated dist outputs aside and running the actual Turbo prompts build with cache bypass, then package checks and root verify. No prompt, test harness, or model-facing behavior changes. Live model, UI and device evidence N/A for build ordering.

Implemented locally in15a1c08c95: prompts build now uses ^build. Moved common/prompts dist outputs aside and ran actual Turbo build with --force:2tasks pass in dependency order. All33prompts tests, types/lint and full root verify377tasks plus later audits pass. Generated outputs restored by build; old outputs preserved outside repository. No new tests/harness or prompt changes. Delivery remains open.