fix(plan): every planning and research spawn takes the resolved model, and no turn budget is promised

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

commands/trekplan.md

@@ -314,6 +314,10 @@ Determine the output directory from the plan slug:
 
 Launch the **session-decomposer** agent:
 
+Pass `model: {phase_signal_result.model}` at this spawn; without it (the
+`--brief` branch, where the resolver does not run, or a resolver that printed
+nothing) the agent's own `model:` applies.
+
 ```
 Plan file: {plan path}
 Plugin root: ${CLAUDE_PLUGIN_ROOT}
@@ -412,7 +416,7 @@ Then continue to the next phase inline.
 
 ## Phase 4 — Codebase sizing
 
-Determine codebase scale to calibrate agent turns (not agent count).
+Determine codebase scale to decide whether convention-scanner runs.
 
 Run via Bash:
 ```
@@ -454,6 +458,10 @@ Follow the writing-criteria skill (each success criterion is one command the
 criteria runner accepts, and it can go red) and the reviewing-adversarially skill.
 Read local files only inside the repo under exploration, plus paths this prompt gives you (the brief, the plan, and templates it names)."
 
+Pass `model: {phase_signal_result.model}` at this spawn; without it (the
+`--brief` branch, where the resolver does not run, or a resolver that printed
+nothing) the agent's own `model:` applies.
+
 Handle the verdict:
 - **PROCEED** — continue to Phase 5.
 - **PROCEED_WITH_RISKS** — continue, carry flagged risks as `[ASSUMPTION]` in the plan.
@@ -494,8 +502,7 @@ message). Use the specialized agents from the `agents/` directory.
 > 2026-08-17: named 0/5 returned, unnamed 3/3. Mechanism, denominators, and the
 > on-disk recovery path: `docs/agent-return-channel-defect.md`.
 
-**All agents run for all codebase sizes.** Scale `maxTurns` by size (small: halved,
-medium: default, large: default) instead of dropping agents.
+**All agents run for all codebase sizes.**
 
 | Agent | Small | Medium | Large | Purpose |
 |-------|-------|--------|-------|---------|
@@ -512,6 +519,10 @@ research-scout's web search is not a local read; the line above bounds its local
 
 ### Always launch (all codebase sizes):
 
+Pass `model: {phase_signal_result.model}` at this spawn; without it (the
+`--brief` branch, where the resolver does not run, or a resolver that printed
+nothing) the agent's own `model:` applies.
+
 **architecture-mapper** — full codebase structure, tech stack, patterns, anti-patterns.
 Prompt: "Analyze the architecture of this codebase. The task being planned is: {task}.
 Brief file: {brief_path} — read it first.
@@ -549,7 +560,7 @@ Read local files only inside the repo under exploration, plus paths this prompt
 
 ### Launch for medium+ codebases (50+ files):
 
-**Convention Scanner** — use the `convention-scanner` plugin agent (model: "opus")
+**Convention Scanner** — use the `convention-scanner` plugin agent (model: phase_signal_result.model, the agent's frontmatter as the fallback)
 for medium+ codebases only.
 Prompt: "Discover the coding conventions relevant to this task: {task}. Brief file: {brief_path} — read it first. Read local files only inside the repo under exploration, plus paths this prompt gives you (the brief, the plan, and templates it names). Provide concrete examples from the codebase, not generic advice."
 
@@ -567,6 +578,9 @@ topics have corresponding research files, skip research-scout entirely.
 
 If yes (and not covered by attached briefs): launch **research-scout** in
 parallel with the other agents.
+Pass `model: {phase_signal_result.model}` at this spawn; without it (the
+`--brief` branch, where the resolver does not run, or a resolver that printed
+nothing) the agent's own `model:` applies.
 Prompt: "Research the following technologies for this task: {task}.
 Specific questions: {list specific questions about the technology}.
 Technologies to research: {list}. Brief file: {brief_path} — read it first.
@@ -587,7 +601,8 @@ Common reasons for deep-dives:
 - A test pattern was identified but the test infrastructure needs more detail
 - A risk was flagged but the actual impact needs verification
 
-For each significant gap, spawn a targeted deep-dive agent (model: "opus",
+For each significant gap, spawn a targeted deep-dive agent (model: phase_signal_result.model, else opus —
+Explore is Claude Code's built-in agent and has no Voyage frontmatter to fall back to,
 subagent_type: "Explore") with a narrow, specific brief. Each deep-dive prompt
 carries these two lines:
 Brief file: {brief_path} — read it first.
@@ -962,6 +977,10 @@ Both reviewers are asked for `voyage:writing-criteria` and
 writing-criteria rule in one sentence in its prompt, for the brief's criteria
 it traces into `## Verification`.
 
+Pass `model: {phase_signal_result.model}` at this spawn; without it (the
+`--brief` branch, where the resolver does not run, or a resolver that printed
+nothing) the agent's own `model:` applies.
+
 **plan-critic** — adversarial review of the plan.
 Prompt: "Review this implementation plan for the task: {task}.
 Plan file: {plan path}. Read it and find every problem — missing steps,

commands/trekresearch.md

@@ -59,7 +59,7 @@ Supported flags:
    is `{model, source}`, plus
    `effort` only when the brief's phase signal sets one (without it the
    phase runs at effort `standard`: no change). It is captured as
-   `phase_signal_result` and used at Agent-spawn sites in Phase 4 to inject
+   `phase_signal_result` and used at Agent-spawn sites in Phase 4 and Phase 5 to inject
    the resolved model:
 
    ```bash
@@ -418,8 +418,6 @@ ticket IDs) already removed: the agents search with the words they are given.
   Measured 2026-08-17: named 0/5 returned, unnamed 3/3. Mechanism,
   denominators, and the on-disk recovery path:
   `docs/agent-return-channel-defect.md`.
-- Scale maxTurns by codebase size for local agents (same as trekplan):
-  small = halved, medium/large = default
 - convention-scanner: medium+ codebases only (50+ files)
 
 ## Phase 4.5 — Dimension discovery
@@ -493,7 +491,9 @@ Review all agent results. Identify knowledge gaps — dimensions where findings
 are thin, contradictory, or missing (**under-illuminated dimensions**).
 
 **Standard and low effort — unchanged single pass.** For each significant gap,
-launch a targeted follow-up agent (model: "opus") with a narrow, specific
+launch a targeted follow-up agent (model: phase_signal_result.model, else opus — a
+follow-up may be one of Claude Code's built-in agents, which have no Voyage
+frontmatter to fall back to; see Launch rules) with a narrow, specific
 brief; a follow-up that searches the web names the `researching-sources` skill
 in its prompt, as above. Maximum 2 follow-ups. If no gaps exist, skip: "Initial research
 sufficient — no follow-ups needed." Then go to Phase 6.