chore(voyage): pin all sub-agents to Opus permanently (operator request)

Flip model: sonnet → model: opus across 20 agent files, 4 prose references
in commands (trekplan, trekresearch), trekendsession command frontmatter,
and CLAUDE.md tables. Aligns CLAUDE.md premium-profile row to actual
premium.yaml content (all-opus, which has been the case since v4.1.0 but
the doc was drift). Companion to VOYAGE_PROFILE=premium env-var (set in
~/.zshenv same day) — env-var governs orchestrator phase model; this
commit governs sub-agent models which are frontmatter-pinned and not
reachable by the profile resolver.

npm test: 516 pass, 0 fail, 2 skipped (unchanged from baseline).

Operator rationale: complete Opus coverage across all Voyage activity,
including the 20 sub-agents that the profile system does not control
(architecture-mapper, task-finder, plan-critic, scope-guardian,
brief-reviewer, code-correctness-reviewer, brief-conformance-reviewer,
review-coordinator, session-decomposer, plus the 6 researcher agents,
plus the 5 codebase-analysis agents).

Cost implication: sub-agent runs ~5x more expensive vs sonnet. Accepted.

plugins/voyage/agents/architecture-mapper.md

@@ -21,7 +21,7 @@ description: |
   Direct architecture analysis request triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: cyan
 tools: ["Read", "Glob", "Grep", "Bash"]
 ---

plugins/voyage/agents/brief-conformance-reviewer.md

@@ -5,7 +5,7 @@ description: |
   against the task brief — every Success Criterion must trace to delivered
   code, every Non-Goal must remain unbuilt. Emits findings with rule_keys
   from the canonical RULE_CATALOGUE. Never praises.
-model: sonnet
+model: opus
 color: magenta
 tools: ["Read", "Glob", "Grep"]
 ---

plugins/voyage/agents/brief-reviewer.md

@@ -23,7 +23,7 @@ description: |
   Brief review request triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: magenta
 tools: ["Read", "Glob", "Grep"]
 ---

plugins/voyage/agents/code-correctness-reviewer.md

@@ -6,7 +6,7 @@ description: |
   cross-file regressions, test coverage gaps, placeholder code, security
   surface, hidden dependencies. Cites file:line for every finding. Never
   praises.
-model: sonnet
+model: opus
 color: red
 tools: ["Read", "Glob", "Grep"]
 ---

plugins/voyage/agents/community-researcher.md

@@ -24,7 +24,7 @@ description: |
   finds the practical signal that helps teams make adoption decisions.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: green
 tools: ["WebSearch", "WebFetch", "mcp__tavily__tavily_search", "mcp__tavily__tavily_research"]
 ---

plugins/voyage/agents/contrarian-researcher.md

@@ -24,7 +24,7 @@ description: |
   but to ensure the final recommendation is genuinely considered.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: red
 tools: ["WebSearch", "WebFetch", "mcp__tavily__tavily_search", "mcp__tavily__tavily_research"]
 ---

plugins/voyage/agents/convention-scanner.md

@@ -23,7 +23,7 @@ description: |
   Direct convention discovery request triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: yellow
 tools: ["Read", "Glob", "Grep", "Bash"]
 ---

plugins/voyage/agents/dependency-tracer.md

@@ -21,7 +21,7 @@ description: |
   Impact analysis request triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: blue
 tools: ["Read", "Glob", "Grep", "Bash"]
 ---

plugins/voyage/agents/docs-researcher.md

@@ -23,7 +23,7 @@ description: |
   microsoft_docs_fetch) that docs-researcher uses for higher-quality results.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: blue
 tools: ["WebSearch", "WebFetch", "Read", "mcp__tavily__tavily_search", "mcp__tavily__tavily_research", "mcp__microsoft-learn__microsoft_docs_search", "mcp__microsoft-learn__microsoft_docs_fetch"]
 ---

plugins/voyage/agents/gemini-bridge.md

@@ -24,7 +24,7 @@ description: |
   Direct request for Gemini research on a complex architectural question triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: magenta
 tools: ["mcp__gemini-mcp__gemini_deep_research", "mcp__gemini-mcp__gemini_get_research_status", "mcp__gemini-mcp__gemini_get_research_result", "mcp__gemini-mcp__gemini_research_followup"]
 ---

plugins/voyage/agents/git-historian.md

@@ -21,7 +21,7 @@ description: |
   Git history analysis request triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: yellow
 tools: ["Bash", "Read", "Glob", "Grep"]
 ---

plugins/voyage/agents/plan-critic.md

@@ -21,7 +21,7 @@ description: |
   Plan review request triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: red
 tools: ["Read", "Glob", "Grep"]
 ---

plugins/voyage/agents/planning-orchestrator.md

@@ -137,7 +137,7 @@ medium: default, large: default) rather than dropping agents.
 | `research-scout` | Conditional | Conditional | Conditional | External docs (only when unfamiliar tech detected AND not covered by briefs) |
 | `convention-scanner` | No | Yes | Yes | Coding conventions, naming, style, test patterns |
 
-**Convention Scanner** — use the `convention-scanner` plugin agent (model: "sonnet")
+**Convention Scanner** — use the `convention-scanner` plugin agent (model: "opus")
 for medium+ codebases only. Pass the task description as context.
 
 **research-scout** — launch conditionally if the task involves technologies, APIs,

plugins/voyage/agents/research-scout.md

@@ -21,7 +21,7 @@ description: |
   Research request for external technology triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: blue
 tools: ["WebSearch", "WebFetch", "Read"]
 ---

plugins/voyage/agents/review-coordinator.md

@@ -6,7 +6,7 @@ description: |
   applies BOUNDED operations: deduplication, severity ranking, HubSpot
   Judge filters, Cloudflare reasonableness filter, verdict computation.
   Synthesis-level inference across files is forbidden in v1.0.
-model: sonnet
+model: opus
 color: yellow
 tools: ["Read", "Glob", "Grep"]
 ---

plugins/voyage/agents/risk-assessor.md

@@ -21,7 +21,7 @@ description: |
   Risk analysis request triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: yellow
 tools: ["Read", "Glob", "Grep", "Bash"]
 ---

plugins/voyage/agents/scope-guardian.md

@@ -21,7 +21,7 @@ description: |
   Scope verification request triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: magenta
 tools: ["Read", "Glob", "Grep"]
 ---

plugins/voyage/agents/security-researcher.md

@@ -23,7 +23,7 @@ description: |
   using CVE databases, OWASP categories, and verified audit reports.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: red
 tools: ["WebSearch", "WebFetch", "mcp__tavily__tavily_search", "mcp__tavily__tavily_research"]
 ---

plugins/voyage/agents/session-decomposer.md

@@ -22,7 +22,7 @@ description: |
   Plan decomposition request for parallel headless execution.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: green
 tools: ["Read", "Glob", "Grep", "Write"]
 ---

plugins/voyage/agents/task-finder.md

@@ -22,7 +22,7 @@ description: |
   Direct code discovery request triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: green
 tools: ["Read", "Glob", "Grep", "Bash"]
 ---

plugins/voyage/agents/test-strategist.md

@@ -21,7 +21,7 @@ description: |
   Test planning request triggers the agent.
   </commentary>
   </example>
-model: sonnet
+model: opus
 color: green
 tools: ["Read", "Glob", "Grep", "Bash"]
 ---