* feat: wire execution-boundary interception points
Adds the typed interception contexts (`crewai/hooks/contexts.py`) and wires
the `execution_start`, `input`, `output`, and `execution_end` points for both
crews and flows through the dispatcher. `prepare_kickoff` and
`Flow.kickoff_async` fire `execution_start`/`input` so a hook can rewrite
resolved inputs before the run, while `Crew._create_crew_output` and the flow
tail fire `output`/`execution_end` so the final result can be observed or
replaced. Closes the eight critical-path points without touching the legacy
hooks.
* fix: correct execution-boundary hook ordering and input aliasing
Reworks the crew and flow boundary seams flagged in review. `OUTPUT` and
`EXECUTION_END` now run before the completion event (`CrewKickoffCompletedEvent`
and `FlowFinishedEvent`) so a `HookAborted` no longer leaves a spurious
completed signal and a returned payload replacement is honored on the emitted
and returned result. Boundary contexts alias `inputs` to the same object as
`payload` instead of a fresh dict from `or`, so in-place edits survive
read-back. Flows re-publish the resolved inputs into `flow_inputs` baggage
after the `INPUT` hook so trigger-payload injection observes hook rewrites, and
a resumed flow now dispatches `OUTPUT`/`EXECUTION_END` on its completion path.
* chore: drop redundant seam comments from execution-boundary wiring
Removes two inline comments narrating the OUTPUT/EXECUTION_END dispatch
ordering in `crew.py` and the flow runtime, plus a stray sentence about
enterprise adapters in the conformance-suite docstring. Comment-only
cleanup, no behavior change.
* fix: keep crew output typed across boundary hook dispatch
`_create_crew_output` reassigned `crew_output` from the hook contexts'
`payload`, which is typed `Any`, so mypy flagged `no-any-return` at the
function's return. Cast the payload back to `CrewOutput` after each
dispatch and split the `ExecutionEndContext` construction to satisfy
`ruff format`'s line-length limit.
