Co-authored-by: cswatt <[email protected]>

Implements the core aggregation logic for evaluation logging (EVALLOG).
Aggregates flag evaluations by key before flushing to reduce network overhead.

Key components:
- EvaluationEventsProcessor: Aggregates evaluations with time/size-based flushing
  - Time-based: Configurable interval (default 10s, range 1-60s)
  - Size-based: Auto-flush at 1000 unique aggregations
  - Shutdown: Final flush on processor.stop()

- AggregationKey: Composite key for grouping evaluations
  - Groups by: flag, variant, allocation, targeting key, error code
  - EVALLOG.8: Omits variant/allocation for DEFAULT/ERROR reasons

- AggregationStats: Tracks aggregated statistics per key
  - Count, first/last timestamps, last error message
  - Thread-safe with @volatile fields and synchronized blocks

- EvaluationEventWriter: Interface for persisting FlagEvaluation events
  - Abstraction allows testing without storage implementation

Test infrastructure:
- FlagEvaluationAssert: Custom assertions for validation
- FlagEvaluationForgeryFactory: Test data generator
- EvaluationContextForgeryFactory: Context data generator

Uses BatchedFlagEvaluations.FlagEvaluation from PR #1 schema.
No runtime integration - isolated business logic only.

EVALLOG compliance: 2, 3, 4, 5, 8, 10, 11, 13

Implements persistence and network transport for evaluation events.

Storage layer (EvaluationEventRecordWriter):
- Implements EvaluationEventWriter interface from PR #2
- Serializes FlagEvaluation events to JSON
- Persists to SDK Core storage as RawBatchEvent
- Thread-safe with synchronized writes

Network layer (EvaluationsRequestFactory):
- Creates HTTP requests to /api/v2/flagevaluations endpoint
- Builds BatchedFlagEvaluations payload per EVALLOG.1 specification
- Wraps individual FlagEvaluation events with top-level context:
  - Service metadata (service, version, env)
  - Device info (name, type, brand, model)
  - OS info (name, version)
  - RUM context (application.id, view.url)
- Handles malformed events gracefully (skip and log)
- Standard EVP headers (API key, origin, origin version, request ID)

EVALLOG.1 compliance:
- Endpoint: /api/v2/flagevaluations
- Content-Type: application/json
- Payload: {"context": {...}, "flagEvaluations": [...]}

Depends on BatchedFlagEvaluations model from PR #1.
Uses EvaluationEventWriter interface from PR #2.

Implements persistence and network transport for evaluation events.

Storage layer (EvaluationEventRecordWriter):
- Implements EvaluationEventWriter interface from PR #2
- Serializes FlagEvaluation events to JSON
- Persists to SDK Core storage as RawBatchEvent
- Thread-safe with synchronized writes

Network layer (EvaluationsRequestFactory):
- Creates HTTP requests to /api/v2/flagevaluations endpoint
- Builds BatchedFlagEvaluations payload per EVALLOG.1 specification
- Wraps individual FlagEvaluation events with top-level context:
  - Service metadata (service, version, env)
  - Device info (name, type, brand, model)
  - OS info (name, version)
  - RUM context (application.id, view.url)
- Handles malformed events gracefully (skip and log)
- Standard EVP headers (API key, origin, origin version, request ID)

EVALLOG.1 compliance:
- Endpoint: /api/v2/flagevaluations
- Content-Type: application/json
- Payload: {"context": {...}, "flagEvaluations": [...]}

Depends on BatchedFlagEvaluations model from PR #1.
Uses EvaluationEventWriter interface from PR #2.

Implements the core aggregation logic for evaluation logging (EVALLOG).
Aggregates flag evaluations by key before flushing to reduce network overhead.

Key components:
- EvaluationEventsProcessor: Aggregates evaluations with time/size-based flushing
  - Time-based: Configurable interval (default 10s, range 1-60s)
  - Size-based: Auto-flush at 1000 unique aggregations
  - Shutdown: Final flush on processor.stop()

- AggregationKey: Composite key for grouping evaluations
  - Groups by: flag, variant, allocation, targeting key, error code
  - EVALLOG.8: Omits variant/allocation for DEFAULT/ERROR reasons

- AggregationStats: Tracks aggregated statistics per key
  - Count, first/last timestamps, last error message
  - Thread-safe with @volatile fields and synchronized blocks

- EvaluationEventWriter: Interface for persisting FlagEvaluation events
  - Abstraction allows testing without storage implementation

Test infrastructure:
- FlagEvaluationAssert: Custom assertions for validation
- FlagEvaluationForgeryFactory: Test data generator
- EvaluationContextForgeryFactory: Context data generator

Uses BatchedFlagEvaluations.FlagEvaluation from PR #1 schema.
No runtime integration - isolated business logic only.

EVALLOG compliance: 2, 3, 4, 5, 8, 10, 11, 13

Implements the core aggregation logic for evaluation logging (EVALLOG).
Aggregates flag evaluations by key before flushing to reduce network overhead.

Key components:
- EvaluationEventsProcessor: Aggregates evaluations with time/size-based flushing
  - Time-based: Configurable interval (default 10s, range 1-60s)
  - Size-based: Auto-flush at 1000 unique aggregations
  - Shutdown: Final flush on processor.stop()

- AggregationKey: Composite key for grouping evaluations
  - Groups by: flag, variant, allocation, targeting key, error code
  - EVALLOG.8: Omits variant/allocation for DEFAULT/ERROR reasons

- AggregationStats: Tracks aggregated statistics per key
  - Count, first/last timestamps, last error message
  - Thread-safe with @volatile fields and synchronized blocks

- EvaluationEventWriter: Interface for persisting FlagEvaluation events
  - Abstraction allows testing without storage implementation

Test infrastructure:
- FlagEvaluationAssert: Custom assertions for validation
- FlagEvaluationForgeryFactory: Test data generator
- EvaluationContextForgeryFactory: Context data generator

Uses BatchedFlagEvaluations.FlagEvaluation from PR #1 schema.
No runtime integration - isolated business logic only.

EVALLOG compliance: 2, 3, 4, 5, 8, 10, 11, 13

Implements the core aggregation logic for evaluation logging (EVALLOG).
Aggregates flag evaluations by key before flushing to reduce network overhead.

Key components:
- EvaluationEventsProcessor: Aggregates evaluations with time/size-based flushing
  - Time-based: Configurable interval (default 10s, range 1-60s)
  - Size-based: Auto-flush at 1000 unique aggregations
  - Shutdown: Final flush on processor.stop()

- AggregationKey: Composite key for grouping evaluations
  - Groups by: flag, variant, allocation, targeting key, error code
  - EVALLOG.8: Omits variant/allocation for DEFAULT/ERROR reasons

- AggregationStats: Tracks aggregated statistics per key
  - Count, first/last timestamps, last error message
  - Thread-safe with @volatile fields and synchronized blocks

- EvaluationEventWriter: Interface for persisting FlagEvaluation events
  - Abstraction allows testing without storage implementation

Test infrastructure:
- FlagEvaluationAssert: Custom assertions for validation
- FlagEvaluationForgeryFactory: Test data generator
- EvaluationContextForgeryFactory: Context data generator

Uses BatchedFlagEvaluations.FlagEvaluation from PR #1 schema.
No runtime integration - isolated business logic only.

EVALLOG compliance: 2, 3, 4, 5, 8, 10, 11, 13

Implements the core aggregation logic for evaluation logging (EVALLOG).
Aggregates flag evaluations by key before flushing to reduce network overhead.

Key components:
- EvaluationEventsProcessor: Aggregates evaluations with time/size-based flushing
  - Time-based: Configurable interval (default 10s, range 1-60s)
  - Size-based: Auto-flush at 1000 unique aggregations
  - Shutdown: Final flush on processor.stop()

- AggregationKey: Composite key for grouping evaluations
  - Groups by: flag, variant, allocation, targeting key, error code
  - EVALLOG.8: Omits variant/allocation for DEFAULT/ERROR reasons

- AggregationStats: Tracks aggregated statistics per key
  - Count, first/last timestamps, last error message
  - Thread-safe with @volatile fields and synchronized blocks

- EvaluationEventWriter: Interface for persisting FlagEvaluation events
  - Abstraction allows testing without storage implementation

Test infrastructure:
- FlagEvaluationAssert: Custom assertions for validation
- FlagEvaluationForgeryFactory: Test data generator
- EvaluationContextForgeryFactory: Context data generator

Uses BatchedFlagEvaluations.FlagEvaluation from PR #1 schema.
No runtime integration - isolated business logic only.

EVALLOG compliance: 2, 3, 4, 5, 8, 10, 11, 13

Implements the core aggregation logic for evaluation logging (EVALLOG).
Aggregates flag evaluations by key before flushing to reduce network overhead.

Key components:
- EvaluationEventsProcessor: Aggregates evaluations with time/size-based flushing
  - Time-based: Configurable interval (default 10s, range 1-60s)
  - Size-based: Auto-flush at 1000 unique aggregations
  - Shutdown: Final flush on processor.stop()

- AggregationKey: Composite key for grouping evaluations
  - Groups by: flag, variant, allocation, targeting key, error code
  - EVALLOG.8: Omits variant/allocation for DEFAULT/ERROR reasons

- AggregationStats: Tracks aggregated statistics per key
  - Count, first/last timestamps, last error message
  - Thread-safe with @volatile fields and synchronized blocks

- EvaluationEventWriter: Interface for persisting FlagEvaluation events
  - Abstraction allows testing without storage implementation

Test infrastructure:
- FlagEvaluationAssert: Custom assertions for validation
- FlagEvaluationForgeryFactory: Test data generator
- EvaluationContextForgeryFactory: Context data generator

Uses BatchedFlagEvaluations.FlagEvaluation from PR #1 schema.
No runtime integration - isolated business logic only.

EVALLOG compliance: 2, 3, 4, 5, 8, 10, 11, 13

Implements the core aggregation logic for evaluation logging (EVALLOG).
Aggregates flag evaluations by key before flushing to reduce network overhead.

Key components:
- EvaluationEventsProcessor: Aggregates evaluations with time/size-based flushing
  - Time-based: Configurable interval (default 10s, range 1-60s)
  - Size-based: Auto-flush at 1000 unique aggregations
  - Shutdown: Final flush on processor.stop()

- AggregationKey: Composite key for grouping evaluations
  - Groups by: flag, variant, allocation, targeting key, error code
  - EVALLOG.8: Omits variant/allocation for DEFAULT/ERROR reasons

- AggregationStats: Tracks aggregated statistics per key
  - Count, first/last timestamps, last error message
  - Thread-safe with @volatile fields and synchronized blocks

- EvaluationEventWriter: Interface for persisting FlagEvaluation events
  - Abstraction allows testing without storage implementation

Test infrastructure:
- FlagEvaluationAssert: Custom assertions for validation
- FlagEvaluationForgeryFactory: Test data generator
- EvaluationContextForgeryFactory: Context data generator

Uses BatchedFlagEvaluations.FlagEvaluation from PR #1 schema.
No runtime integration - isolated business logic only.

EVALLOG compliance: 2, 3, 4, 5, 8, 10, 11, 13

Implements the core aggregation logic for evaluation logging (EVALLOG).
Aggregates flag evaluations by key before flushing to reduce network overhead.

Key components:
- EvaluationEventsProcessor: Aggregates evaluations with time/size-based flushing
  - Time-based: Configurable interval (default 10s, range 1-60s)
  - Size-based: Auto-flush at 1000 unique aggregations
  - Shutdown: Final flush on processor.stop()

- AggregationKey: Composite key for grouping evaluations
  - Groups by: flag, variant, allocation, targeting key, error code
  - EVALLOG.8: Omits variant/allocation for DEFAULT/ERROR reasons

- AggregationStats: Tracks aggregated statistics per key
  - Count, first/last timestamps, last error message
  - Thread-safe with @volatile fields and synchronized blocks

- EvaluationEventWriter: Interface for persisting FlagEvaluation events
  - Abstraction allows testing without storage implementation

Test infrastructure:
- FlagEvaluationAssert: Custom assertions for validation
- FlagEvaluationForgeryFactory: Test data generator
- EvaluationContextForgeryFactory: Context data generator

Uses BatchedFlagEvaluations.FlagEvaluation from PR #1 schema.
No runtime integration - isolated business logic only.

EVALLOG compliance: 2, 3, 4, 5, 8, 10, 11, 13

Implements the core aggregation logic for evaluation logging (EVALLOG).
Aggregates flag evaluations by key before flushing to reduce network overhead.

Key components:
- EvaluationEventsProcessor: Aggregates evaluations with time/size-based flushing
  - Time-based: Configurable interval (default 10s, range 1-60s)
  - Size-based: Auto-flush at 1000 unique aggregations
  - Shutdown: Final flush on processor.stop()

- AggregationKey: Composite key for grouping evaluations
  - Groups by: flag, variant, allocation, targeting key, error code
  - EVALLOG.8: Omits variant/allocation for DEFAULT/ERROR reasons

- AggregationStats: Tracks aggregated statistics per key
  - Count, first/last timestamps, last error message
  - Thread-safe with @volatile fields and synchronized blocks

- EvaluationEventWriter: Interface for persisting FlagEvaluation events
  - Abstraction allows testing without storage implementation

Test infrastructure:
- FlagEvaluationAssert: Custom assertions for validation
- FlagEvaluationForgeryFactory: Test data generator
- EvaluationContextForgeryFactory: Context data generator

Uses BatchedFlagEvaluations.FlagEvaluation from PR #1 schema.
No runtime integration - isolated business logic only.

EVALLOG compliance: 2, 3, 4, 5, 8, 10, 11, 13

Implements the core aggregation logic for evaluation logging (EVALLOG).
Aggregates flag evaluations by key before flushing to reduce network overhead.

Key components:
- EvaluationEventsProcessor: Aggregates evaluations with time/size-based flushing
  - Time-based: Configurable interval (default 10s, range 1-60s)
  - Size-based: Auto-flush at 1000 unique aggregations
  - Shutdown: Final flush on processor.stop()

- AggregationKey: Composite key for grouping evaluations
  - Groups by: flag, variant, allocation, targeting key, error code
  - EVALLOG.8: Omits variant/allocation for DEFAULT/ERROR reasons

- AggregationStats: Tracks aggregated statistics per key
  - Count, first/last timestamps, last error message
  - Thread-safe with @volatile fields and synchronized blocks

- EvaluationEventWriter: Interface for persisting FlagEvaluation events
  - Abstraction allows testing without storage implementation

Test infrastructure:
- FlagEvaluationAssert: Custom assertions for validation
- FlagEvaluationForgeryFactory: Test data generator
- EvaluationContextForgeryFactory: Context data generator

Uses BatchedFlagEvaluations.FlagEvaluation from PR #1 schema.
No runtime integration - isolated business logic only.

EVALLOG compliance: 2, 3, 4, 5, 8, 10, 11, 13