refactor: apply minimal tfcode branding

- Rename packages/opencode → packages/tfcode (directory only)
- Rename bin/opencode → bin/tfcode (CLI binary)
- Rename .opencode → .tfcode (config directory)
- Update package.json name and bin field
- Update config directory path references (.tfcode)
- Keep internal code references as 'opencode' for easy upstream sync
- Keep @opencode-ai/* workspace package names

This minimal branding approach allows clean merges from upstream
opencode repository while providing tfcode branding for users.

packages/tfcode/script/schema.ts

@@ -0,0 +1,63 @@
+#!/usr/bin/env bun
+
+import { z } from "zod"
+import { Config } from "../src/config/config"
+import { TuiConfig } from "../src/config/tui"
+
+function generate(schema: z.ZodType) {
+  const result = z.toJSONSchema(schema, {
+    io: "input", // Generate input shape (treats optional().default() as not required)
+    /**
+     * We'll use the `default` values of the field as the only value in `examples`.
+     * This will ensure no docs are needed to be read, as the configuration is
+     * self-documenting.
+     *
+     * See https://json-schema.org/draft/2020-12/draft-bhutton-json-schema-validation-00#rfc.section.9.5
+     */
+    override(ctx) {
+      const schema = ctx.jsonSchema
+
+      // Preserve strictness: set additionalProperties: false for objects
+      if (
+        schema &&
+        typeof schema === "object" &&
+        schema.type === "object" &&
+        schema.additionalProperties === undefined
+      ) {
+        schema.additionalProperties = false
+      }
+
+      // Add examples and default descriptions for string fields with defaults
+      if (schema && typeof schema === "object" && "type" in schema && schema.type === "string" && schema?.default) {
+        if (!schema.examples) {
+          schema.examples = [schema.default]
+        }
+
+        schema.description = [schema.description || "", `default: \`${schema.default}\``]
+          .filter(Boolean)
+          .join("\n\n")
+          .trim()
+      }
+    },
+  }) as Record<string, unknown> & {
+    allowComments?: boolean
+    allowTrailingCommas?: boolean
+  }
+
+  // used for json lsps since config supports jsonc
+  result.allowComments = true
+  result.allowTrailingCommas = true
+
+  return result
+}
+
+const configFile = process.argv[2]
+const tuiFile = process.argv[3]
+
+console.log(configFile)
+await Bun.write(configFile, JSON.stringify(generate(Config.Info), null, 2))
+
+if (tuiFile) {
+  console.log(tuiFile)
+  await Bun.write(tuiFile, JSON.stringify(generate(TuiConfig.Info), null, 2))
+}