docs: add hook points documentation and config template

.archeflow/config.yaml

@@ -30,3 +30,26 @@ memory:
 progress:
   enabled: true
   file: .archeflow/progress.md
+
+# Hooks — commands to run at orchestration lifecycle events.
+# Uncomment and customize as needed.
+#
+# hooks:
+#   run-start:
+#     command: "echo 'ArcheFlow run starting'"
+#     fail_action: warn        # warn | abort
+#   phase-complete:
+#     command: "./scripts/on-phase-complete.sh"
+#     fail_action: warn
+#   agent-complete:
+#     command: "./scripts/on-agent-complete.sh"
+#     fail_action: warn
+#   pre-merge:
+#     command: "./scripts/pre-merge-checks.sh"
+#     fail_action: abort       # abort recommended — blocks bad merges
+#   post-merge:
+#     command: "./scripts/post-merge-notify.sh"
+#     fail_action: warn
+#   run-complete:
+#     command: "./scripts/on-run-complete.sh"
+#     fail_action: warn