feat(trekresearch): add deep-research in-context adapter + self-check

commands/trekresearch.md

@@ -443,6 +443,45 @@ Write the brief to the `brief_destination` computed in Phase 1:
 
 Create the parent directory if it does not exist.
 
+### Deep-research engine adapter (engine = deep-research only)
+
+**Only when `effective_engine == deep-research`.** The swarm path skips this
+entirely — its findings already flow through Phases 6–7 unchanged (SC1).
+
+Transform the in-context `/deep-research` report INTO
+`@${CLAUDE_PLUGIN_ROOT}/templates/research-brief-template.md` — do NOT paste the
+raw report. Specifically:
+
+- Reduce the report to ≥ 1 `### {Dimension} -- Confidence: {high|medium|low}`
+  entry, each carrying **External findings** bullets with per-claim source URLs.
+  Local findings still come from the local agents (Phase 4) and are merged in per
+  dimension as usual.
+- Emit a numeric `confidence ∈ [0,1]` in frontmatter and a 3-sentence
+  `## Executive Summary` (answer, confidence, key caveat).
+- Populate `## Sources` from the report's citations.
+- **If the report lacks per-claim URLs, lower the confidence and note the gap in
+  `## Open Questions` — do NOT fabricate URLs.** Provenance you cannot cite is not
+  provenance.
+- If the report is large, bound the transform to the top dimensions to avoid
+  context truncation.
+
+### Output self-check (engine = deep-research only)
+
+**Only when `effective_engine == deep-research`.** After writing to
+`brief_destination`, run the output validator and repair-or-fall-back. This mirrors
+the trekplan Phase-8 write→validate→repair self-check; the swarm path does NOT run
+it, so swarm behavior is unchanged (SC1):
+
+```bash
+node ${CLAUDE_PLUGIN_ROOT}/lib/validators/research-validator.mjs --json "{brief_destination}"
+```
+
+On `valid: false`, repair the brief to satisfy the reported errors and re-run the
+validator. If it cannot be made valid (e.g. the report was too thin to yield even
+one dimension), set `effective_engine = swarm`, fall back to the swarm engine for
+this run (and log the fallback per the Engine selection step), rather than emit an
+invalid brief.
+
 ## Phase 8 — Present and track
 
 Present a summary to the user: