browser_execute: resolve harness path in tool description

The description references SKILL.md and helpers.py by source-tree path,
which only resolves correctly in dev mode. In compiled binaries the
harness extracts to <dataDir>/harness/ and those source paths don't
exist on disk, so the agent's first read fails.

Template the path: replace packages/bcode-browser/harness/ with
{{HARNESS_DIR}} in the description, and substitute the resolved path
(dev or compiled) in the opencode adapter at make-time. Eager harness
extraction (already in the data-dir relocation commit) guarantees the
files exist before the agent reads the description.

Author: Alezander9

packages/bcode-browser/src/browser-execute.ts

@@ -157,7 +157,7 @@ export const make = Effect.fn("BrowserExecute.make")(function* (dataDir: string)
       }),
     )
 
-  return { parameters, execute }
+  return { parameters, execute, harnessDir }
 })
 
 export * as BrowserExecute from "./browser-execute"

packages/opencode/src/tool/browser-execute.ts

@@ -17,7 +17,10 @@ export const BrowserExecuteTool = Tool.define(
   Effect.gen(function* () {
     const impl = yield* BrowserExecute.make(Global.Path.data)
     return {
-      description: DESCRIPTION,
+      // Substitute the resolved harness path (dev: repo path; compiled:
+      // <dataDir>/harness/) so the SKILL.md / helpers.py references in the
+      // description point at files that actually exist on disk.
+      description: DESCRIPTION.replaceAll("{{HARNESS_DIR}}", impl.harnessDir),
       parameters: impl.parameters,
       execute: (args: Schema.Schema.Type<typeof impl.parameters>, ctx: Tool.Context) =>
         Effect.gen(function* () {

packages/opencode/src/tool/browser-execute.txt

@@ -2,6 +2,6 @@ Execute Python against a connected web browser via the BrowserCode harness.
 
 Use this tool whenever the task requires driving a real browser — automation, scraping, end-to-end testing, or interactive exploration. The harness attaches to the user's running Chrome (local) or a Browser Use cloud browser (remote). A session-scoped daemon holds the CDP connection so consecutive calls share the same browser and tabs.
 
-Before the first `browser_execute` call of a session, you MUST read `packages/bcode-browser/harness/SKILL.md`. It defines the helper surface, the screenshot-driven workflow, remote-browser setup, and gotchas — none of that is repeated here.
+Before the first `browser_execute` call of a session, you MUST read `{{HARNESS_DIR}}/SKILL.md`. It defines the helper surface, the screenshot-driven workflow, remote-browser setup, and gotchas — none of that is repeated here.
 
-Optional: read `packages/bcode-browser/harness/src/browser_harness/helpers.py` when you need an exact signature that SKILL.md does not show.
+Optional: read `{{HARNESS_DIR}}/src/browser_harness/helpers.py` when you need an exact signature that SKILL.md does not show.