Bug: MCP resource @mention dispatches local file read instead of resources/read RPC #17543

Description

Steps to reproduce:

1. Configure an MCP server that exposes resources (e.g. resource://promptd/git-status.sh)
2. In an opencode session, type @git-status.sh — the resource autocompletes correctly
3. Send the message

Expected behavior:
opencode sends a resources/read request to the MCP server with uri: "resource://promptd/git-status.sh". The server handles it and returns the content.

Actual behavior:
opencode constructs a file:// URL using the resource filename resolved against the current working directory (e.g. file:///Users/blink/Code/promptd/git-status.sh) and attempts to read it with its local file read tool. The file doesn't exist at that path, so it fails:

→ Read git-status.sh
Error: File not found: /Users/blink/Code/promptd/git-status.sh

Plugins

none

OpenCode version

1.2.26

Steps to reproduce

1. Configure an MCP server that exposes resources (e.g. resource://promptd/git-status.sh)
2. In an opencode session, type @git-status.sh — the resource autocompletes correctly
3. Send the message

Screenshot and/or share link

No response

Operating System

No response

Terminal

No response