chore(prompt-variance): drop unused assemble and resolve (#1147)

Production already picks family residuals in model-family
policy and glues them in the director constructors. These
two exports had no consumers and would have been a second
pick-and-glue.

Author: TheGreatAxios

packages/prompt-variance/src/assemble.test.ts

@@ -1,5 +1,3 @@
-export { assemble } from "./assemble.js";
-export { resolvePromptVariance } from "./resolve.js";
 export {
   claudeRow,
   defaultRow,

packages/prompt-variance/src/assemble.ts

@@ -58,8 +58,6 @@ packages/opencode-go/src/models.ts: readonly
 # to the exact ts-prune flags so a new dead export in this barrel fails the
 # guard instead of hiding under a whole-file exemption. Remove each entry
 # with the export it names if the public surface shrinks.
-packages/prompt-variance/src/index.ts: assemble
-packages/prompt-variance/src/index.ts: resolvePromptVariance
 packages/prompt-variance/src/index.ts: defaultRow
 packages/prompt-variance/src/index.ts: FAMILY_IDS
 packages/prompt-variance/src/index.ts: FAMILY_ROWS