[EPIC] Share execution graph logic between StaticExecutionGraph and AdaptiveExecutionGraph #2595

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

StaticExecutionGraph (state/execution_graph.rs) and AdaptiveExecutionGraph (state/aqe/mod.rs) carry near-identical copies of most of their logic. Both files are among the most frequently changed in the scheduler (29 and 25 commits in the last 12 months), and the copies have already drifted:

• resolve_stage / rollback_*_stage lose the stage on error in the AQE copy only (AQE: resolve_stage and rollback_*_stage drop the stage from the graph when the conversion fails #2594).
• The AQE update_task_status has dead reset_running_stages handling, lacks the UnResolved late fetch-failure path, and reports a less useful max-failures message (details in AQE: handle executor failure on the adaptive execution path #1986).

Duplicated code:

Describe the solution you'd like

Proposed sub-tasks, each a behaviour-preserving PR (apart from the bug fixes) relying on the existing execution-graph tests:

• Fix the AQE stage-loss bug (AQE: resolve_stage and rollback_*_stage drop the stage from the graph when the conversion fails #2594) so both copies behave the same before they are merged.
• Extract the shared state (job/session ids, status, timestamps, stages, failed_stage_attempts, ...) into a common struct embedded by both graphs, and implement the accessors, revive, is_successful, completed_stages and lost-executor reset once.
• Share the stage-transition methods and processing_stages_update / get_running_stage_id as default trait methods or free functions over the stages map.
• Share reset_stages_internal as a function returning a reset plan; the AQE graph adds its remove_exchange_locations step afterwards. Replace the nested for_each closures with plain loops.
• Break update_task_status into handle_failed_task, handle_successful_task, handle_late_task_for_unresolved_stage and the resubmit/reset post-passes, then share those between the graphs. This also resolves the AQE gaps described in AQE: handle executor failure on the adaptive execution path #1986.
• Share the test-only pop_next_task.

Describe alternatives you've considered

Keep the copies and port each fix by hand. The drift above shows this is already failing.

Additional context

Related: #1986, #2539, #2150. Line references are pinned to commit ea1126c.