feat(llm): route adapters by provider

packages/workflow/tool-workflow/src/index.ts

@@ -57,10 +57,10 @@ type ResolvedConfig = Required<Config>
  */
 const DESCRIPTION = `Run a JavaScript workflow script that orchestrates subagents at scale. Use this for work that fans out across many independent pieces — an audit over many files, a migration, multi-angle research, adversarial verification of findings — where you write the orchestration as a script instead of delegating turn by turn.
 
-The workflow's identity rides the \`meta\` parameter as JSON: required \`name\` (short kebab-case) and \`description\` strings, optional \`whenToUse\` string and \`phases\` array (\`{title, detail?, model?}\`). The \`script\` parameter is the plain JavaScript body ONLY (NOT TypeScript, and NO \`export const meta\` statement — meta is a parameter, not code), running with top-level await; end with \`return <value>\` — the value must be JSON-serializable and is this tool's result.
+The workflow's identity rides the \`meta\` parameter as JSON: required \`name\` (short kebab-case) and \`description\` strings, optional \`whenToUse\` string and \`phases\` array (\`{title, detail?, provider?, model?}\`). The \`script\` parameter is the plain JavaScript body ONLY (NOT TypeScript, and NO \`export const meta\` statement — meta is a parameter, not code), running with top-level await; end with \`return <value>\` — the value must be JSON-serializable and is this tool's result.
 
 Script-body hooks:
-- \`agent(prompt, opts?): Promise<any>\` — run one subagent to completion. Without \`opts.schema\` it resolves to the child's final text; with \`opts.schema\` (an object-rooted JSON Schema using ONLY type/properties/required/additionalProperties/items/enum/const — no oneOf/pattern/format/numeric bounds) it resolves to the validated object. Resolves \`null\` when the child fails (filter with \`.filter(Boolean)\`). Other opts: \`label\` (display), \`phase\` (progress group), \`model\` (override). Anything else (\`effort\`/\`isolation\`/\`agentType\`) is rejected loudly.
+- \`agent(prompt, opts?): Promise<any>\` — run one subagent to completion. Without \`opts.schema\` it resolves to the child's final text; with \`opts.schema\` (an object-rooted JSON Schema using ONLY type/properties/required/additionalProperties/items/enum/const — no oneOf/pattern/format/numeric bounds) it resolves to the validated object. Resolves \`null\` when the child fails (filter with \`.filter(Boolean)\`). Other opts: \`label\` (display), \`phase\` (progress group), \`provider\` and \`model\` (paired LLM target overrides). Anything else (\`effort\`/\`isolation\`/\`agentType\`) is rejected loudly.
 - \`pipeline(items, ...stages): Promise<any[]>\` — run each item through the stages independently with NO barrier between stages (prefer this for multi-stage work). Each stage receives \`(prev, item, index)\`. An ordinary stage throw drops that ITEM to \`null\` and skips its remaining stages.
 - \`parallel(thunks): Promise<any[]>\` — run zero-argument functions concurrently and await ALL of them (a barrier; use only when a stage genuinely needs every prior result together). A throwing thunk resolves to \`null\`.
 - \`phase(title)\` — start a progress phase; \`log(message)\` — narrate progress; \`args\` — the tool call's \`args\` input, verbatim.
@@ -71,7 +71,12 @@ Constraints: concurrency and total-agent caps apply; no filesystem, network, tim
 
 type WorkflowCallArgs = {
   script: string
-  meta: { name: string; description: string; whenToUse?: string; phases?: { title: string; detail?: string; model?: string }[] }
+  meta: {
+    name: string
+    description: string
+    whenToUse?: string
+    phases?: { title: string; detail?: string; provider?: string; model?: string }[]
+  }
   args?: Record<string, unknown>
 }
 
@@ -153,6 +158,7 @@ export function apply(ctx: Context, config: Config): void {
               properties: {
                 title: { type: 'string', required: true, description: 'The phase title phase() calls match by exact string.' },
                 detail: { type: 'string', description: 'Optional one-line description of the phase.' },
+                provider: { type: 'string', description: 'Optional provider override this phase is expected to use.' },
                 model: { type: 'string', description: 'Optional model override this phase is expected to use.' },
               },
             },