Wires the step, agent, subsystem, and flow points onto the dispatcher:
`pre_step`/`post_step`, `tool_selection`, `pre_delegation`, `retry_attempt`,
`memory_write`/`memory_read`, `knowledge_retrieval`, `pre_code_execution`,
`mcp_connect`, `flow_transition`, and `router_decision`, extending the typed-
context module with their contexts. Each seam passes a typed context whose
`payload` a hook may observe, mutate, or replace. Adds the conformance suite
for these points and a new `interception-hooks` doc page with the full
point/payload catalog and the interceptor contract.
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.
