* Build FlowDefinition from Flow DSL metadata
Introduce `FlowDefinition`, a serializable model built from the Flow
DSL's runtime metadata. It becomes the structural contract for Flow
methods, triggers, routers, state, and configuration.
The visualization layer is the first consumer: `flow_structure` and
`build_flow_structure` now project from the definition instead of
re-introspecting the class. The runner still executes from live
registries, but the definition gives future runners a single static
contract to read.
This replaces AST source parsing for router return values, crew
references, and state schema with runtime metadata plus explicit
`@router(paths=...)` or `Literal`/`Enum` return hints. AST parsing was
fragile and could silently fail for dynamic or non-inspectable methods.
The refactor removes obsolete introspection and serializer code:
* Delete `flow_serializer.py`, `flow/utils.py`, and
`visualization/schema.py`
* Move flow structure modeling into `flow_definition.py`
* Simplify visualization building around the static definition contract
* Format files
fix: refine nested flow conditionals and ensure router methods and routes are fully parsed
fix: improve docstrings, typing, and logging coverage across all events
feat: update flow.plot feature with new UI enhancements
chore: apply Ruff linting, reorganize imports, and remove deprecated utilities/files
chore: split constants and utils, clean JS comments, and add typing for linters
tests: strengthen test coverage for flow execution paths and router logic
