Document Notarius credential forwarding

docs/troubleshooting.md

@@ -213,6 +213,40 @@ input validation.
 
 Relevant reference: [Operations: Stage Execution and Continuation Behavior](./operations.md#stage-execution-and-continuation-behavior).
 
+## Notarius credential reference unavailable
+
+Symptom:
+
+- configuration loading reports `secret.unset`, `secret.empty`, or an invalid
+  name for `pipeline.notarius.llm_api_key`, including during inspection or a
+  run that would not execute extraction.
+
+Likely causes:
+
+- the named environment variable is absent or empty;
+- the selected secrets directory lacks a file with that exact name;
+- a process environment variable exists but is empty, so bootstrap correctly
+  leaves it in place; or
+- the Narratio reference name does not match `api_key_env` in the selected
+  Notarius/PromptKit profile.
+
+Safe fix:
+
+- set the exact nonempty environment variable or provide an equivalently named
+  file through the conventional or explicit secrets directory;
+- remove or set the field to `null` when that deployment needs no credential;
+  and
+- use `config show`, `config sources`, and `config diff` to inspect the public
+  reference name and ownership without exposing its value.
+
+Narratio resolves selected credential references during ordinary pipeline
+loading, before stage selection or resume. Credential changes alone do not
+invalidate a completed extraction, but the current reference must still resolve
+for the command to proceed.
+
+Relevant references: [Secrets](./config.md#secrets-handling) and
+[Notarius credential](./config.md#notarius-credential).
+
 ## Notarius executable missing
 
 Symptom:
@@ -361,10 +395,10 @@ Symptom:
 
 Likely causes:
 
-- the executable/config path, pipeline ID, timeout, working directory, or
-  configured output contracts changed;
+- the pipeline ID or configured output contracts changed;
 - a configured prepared reference selector, source, path, checksum, or byte
   size changed;
+- the direct trimmed transcript identity or bytes changed; or
 - the durable bundle, index, lane set, provenance, regular-file status, or
   checksum no longer validates.
 
@@ -374,6 +408,11 @@ Safe fix:
   an unsafe path or bundle symlink error as filesystem corruption or tampering
   and investigate it rather than replacing files manually.
 
+Executable, config path, timeout, working directory, and Notarius credential
+changes are operational and do not by themselves invalidate reusable extraction
+evidence. A newly selected credential must nevertheless resolve during command
+configuration loading.
+
 ## Notarius transitive configuration changed
 
 Symptom:
@@ -726,7 +765,7 @@ Diagnostics:
 
 ```bash
 ls -la /path/to/secrets_dir
-env | sed 's/=.*//' | grep -E 'OBJECT_STORAGE|AWS|AUDITA|SCRIPTORIUM'
+env | sed 's/=.*//' | grep -E 'OBJECT_STORAGE|AWS|AUDITA|NOTARIUS|SCRIPTORIUM'
 ```
 
 Safe fix: