Fix mypy type errors in pool-coordinator services and API wiring

[chrystianmartins]

Motivation

• Resolve static typing errors flagged by mypy across the pool-coordinator package to ensure safer, clearer API surfaces and service logic.
• Make numeric/Decimal conversions and handler/middleware signatures explicit to avoid Any/incompatible-type issues at type-check time.

Description

• Rename the temporary logging handler variable to stream_handler and keep JsonFormatter usage consistent in configure_logging to avoid handler type inference issues in pool-coordinator/app/core/logging.py.
• Make cosine_similarity return a float explicitly instead of an untyped value to remove Any inference in pool-coordinator/app/services/verification.py.
• Introduce DailyEmissionStatus (TypedDict) and annotate get_daily_emission_status to return it, and use the typed remaining_tokens value safely in run_daily_emission in pool-coordinator/app/services/emission.py.
• Harden reputation conversion in emission logic to accept Decimal, numeric, or string inputs and fallback to Decimal("0") for invalid types to avoid Decimal(object) errors in pool-coordinator/app/services/emission.py.
• Add explicit return typing for require_roles and annotate FastAPI middleware dispatch and lifespan signatures for better static checking in pool-coordinator/app/api/dependencies/auth.py and pool-coordinator/app/main.py.

Testing

• Ran mypy app inside pool-coordinator and confirmed success: Success: no issues found in 44 source files.
• Verified the changes compile with static typing and adjusted code paths touched during the typing fixes.

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Codex Task