Enforce bounded run prerequisites

docs/troubleshooting.md

@@ -117,6 +117,40 @@ Safe fix:
 
 Relevant reference: [CLI artifact selection](./cli.md).
 
+## Bounded run prerequisite is unusable
+
+Symptom:
+
+- `run` or `session plan` reports that a prerequisite stage is absent or has a
+  pending, running, failed, stale, or interrupted status before the selected
+  start.
+
+Likely cause:
+
+- `--from` excludes upstream work that has not reached the terminal
+  `succeeded` or `skipped` state in the session manifest.
+
+Diagnostics:
+
+```bash
+narratio session status 2026-04-04
+narratio session plan 2026-04-04 --from render --through analyze
+```
+
+Safe fix:
+
+- widen the bounded range to include the first reported stage, or recover that
+  stage explicitly with `run-stage` before retrying. The failed check does not
+  create a run record or modify the manifest. Narratio does not resume-validate
+  excluded prefix stages, and stages after `--through` are not prerequisites.
+
+If prerequisite statuses are terminal but a selected stage reports a missing,
+unsafe, or checksum-inconsistent artifact, repair the artifact at the stage
+that owns it; do not edit the manifest to bypass the selected stage's concrete
+input validation.
+
+Relevant reference: [Operations: Stage Execution and Continuation Behavior](./operations.md#stage-execution-and-continuation-behavior).
+
 ## Notarius executable missing
 
 Symptom: