Rewrite troubleshooting docs for current render and artifact behavior

docs/troubleshooting.md

@@ -4,30 +4,31 @@ Each entry includes symptom, likely cause, inspection step, and safe fix.
 
 ## Missing required flags
 
-- Symptom: command fails with messages like `--input-file is required`, `--output-file is required`, or `exactly one of --keep or --remove is required`.
-- Likely cause: required command flags were omitted.
-- Inspection: run command help for the failing command:
+- Symptom: command fails with messages like `--input-file is required`, `--output-file is required`, `--format is required`, or `exactly one of --keep or --remove is required`.
+- Likely cause: one or more required flags were omitted.
+- Inspection: run help for the failing command:
   - `go run ./cmd/seriatim merge --help`
   - `go run ./cmd/seriatim trim --help`
   - `go run ./cmd/seriatim normalize --help`
+  - `go run ./cmd/seriatim render --help`
 - Safe fix: provide all required flags; for `trim`, provide exactly one selector mode (`--keep` or `--remove`).
 
 ## Invalid output or report path
 
 - Symptom: errors like `--output-file parent directory ...` or `--report-file parent directory ...`.
-- Likely cause: parent directory does not exist, is not a directory, or path points to an unusable target.
-- Inspection: verify paths:
+- Likely cause: parent directory does not exist, is not a directory, or the target path is unusable.
+- Inspection: verify parent path and permissions:
   - `dirname <path>`
   - `ls -ld <parent-dir>`
-- Safe fix: create/fix the parent directory and rerun; avoid using directory paths directly as output/report file targets.
+- Safe fix: create or fix the parent directory and rerun. Use a file path (not a directory path) for output/report targets.
 
 ## Invalid merge input JSON
 
 - Symptom: merge fails with messages like `parse input file`, `must contain top-level segments array`, `segment 0 missing numeric start`, or `segment 0 words must be an array`.
 - Likely cause: malformed JSON or unsupported/missing fields in a merge input file.
-- Inspection: validate input JSON and required fields (`start`, `end`, `text`):
+- Inspection: validate JSON and required segment fields (`start`, `end`, `text`):
   - `jq . <input-file>`
-- Safe fix: correct the JSON structure and segment/word field types, then rerun `merge`.
+- Safe fix: correct JSON structure and segment/word field types, then rerun `merge`.
 
 ## Invalid normalize input shape
 
@@ -38,13 +39,22 @@ Each entry includes symptom, likely cause, inspection step, and safe fix.
   - `jq 'keys' <input-file>` (for object input)
 - Safe fix: reshape input into one supported form and rerun `normalize`.
 
+## Invalid render input artifact
+
+- Symptom: render fails with messages like `input JSON is malformed` or `input JSON is not a valid seriatim output artifact`.
+- Likely cause: input is malformed JSON or not one of the supported seriatim output schemas.
+- Inspection:
+  - `jq . <input-file>`
+  - compare input shape against `schema/minimal-output.schema.json`, `schema/intermediate-output.schema.json`, and `schema/full-output.schema.json`
+- Safe fix: render only a valid existing seriatim artifact (`seriatim-minimal`, `seriatim-intermediate`, or `seriatim-full`).
+
 ## Invalid speaker map or autocorrect YAML
 
 - Symptom: merge fails with errors such as `must contain at least one match rule`, `must include speaker`, `must include target`, or duplicate match/speaker validation failures.
-- Likely cause: YAML rule file structure/content does not match expected schema.
+- Likely cause: YAML rule file structure/content does not match expected contract.
 - Inspection: check YAML validity and required top-level keys:
-  - `speakers.yml` requires top-level `match` rules.
-  - `autocorrect.yml` requires top-level `autocorrect` rules.
+  - `speakers.yml` requires top-level `match` rules
+  - `autocorrect.yml` requires top-level `autocorrect` rules
 - Safe fix: correct YAML structure and rule content, then rerun `merge`.
 
 ## Unknown module names
@@ -54,14 +64,18 @@ Each entry includes symptom, likely cause, inspection step, and safe fix.
 - Inspection: compare provided module names against defaults in CLI help and config docs.
 - Safe fix: use implemented module names only or remove unsupported modules from comma-separated lists.
 
-## Invalid output schema value
+## Invalid format or schema values
 
-- Symptom: errors like `--output-schema must be one of ...`.
-- Likely cause: unsupported schema value from flag or `SERIATIM_OUTPUT_SCHEMA`.
-- Inspection: check effective value:
+- Symptom:
+  - render: `--format must be "markdown"`
+  - merge/normalize/trim: `--output-schema must be one of ...`
+- Likely cause: unsupported `--format` or `--output-schema` value.
+- Inspection:
   - command flags
-  - `echo "$SERIATIM_OUTPUT_SCHEMA"`
-- Safe fix: use one of `seriatim-minimal`, `seriatim-intermediate`, or `seriatim-full`.
+  - `echo "$SERIATIM_OUTPUT_SCHEMA"` (for merge/normalize defaults)
+- Safe fix:
+  - render: use `--format markdown`
+  - output schema: use `seriatim-minimal`, `seriatim-intermediate`, or `seriatim-full`
 
 ## Invalid trim selector
 
@@ -73,23 +87,23 @@ Each entry includes symptom, likely cause, inspection step, and safe fix.
   - list: `1-10,15,20-25`
 - Safe fix: correct selector syntax and rerun `trim`.
 
-## Schema validation failures
+## Artifact or schema validation failures
 
-- Symptom: errors such as `validate-output: ...` in merge or `input JSON is not a valid seriatim output artifact` in trim.
+- Symptom: errors such as `validate-output: ...`, `input JSON is not a valid seriatim output artifact`, or related schema-validation errors.
 - Likely cause:
-  - merge module order/config produced invalid final artifact (for example, validating before IDs are assigned), or
-  - trim input is not a valid seriatim artifact.
+  - merge module order/config produced an invalid output artifact, or
+  - trim/render input is not a valid seriatim output artifact.
 - Inspection:
-  - for merge: inspect customized module ordering flags.
-  - for trim: verify input artifact against known seriatim schema files in `schema/`.
+  - for merge: inspect customized module ordering flags
+  - for trim/render: validate input against schema files in `schema/`
 - Safe fix:
-  - restore valid merge postprocessing order ending with assigned IDs before validation, or
-  - provide a valid seriatim artifact as trim input.
+  - merge: restore a valid postprocessing order ending with assigned IDs before output validation
+  - trim/render: provide a valid seriatim artifact as input
 
 ## Report write failure
 
 - Symptom: errors like `write --report-file ...` or file-create failures when report writing is requested.
-- Likely cause: report path is not writable or is an invalid target (for example a directory path).
+- Likely cause: report path is not writable or points to an invalid target.
 - Inspection:
   - `ls -ld <report-parent-dir>`
   - verify `--report-file` is a file path, not a directory