[Bug]: opencode plugin template uses removed `app.on` API — fails on every startup

[kire21b]

code-review-graph version

2.3.8

Operating system

macOS

Python version

3.12.4

AI platform

opencode

Output of code-review-graph status

`code-review-graph install --platform opencode` writes
`~/.config/opencode/plugins/crg-plugin.ts` whose factory registers hooks via
`app.on(...)` (EventEmitter style). opencode's current plugin API calls the
factory with `{ project, client, $, directory, worktree }` and expects a hooks
object back — there is no `app`, so the loader fails on every startup and the
plugin never runs:

    level=ERROR message="failed to load plugin" path=.../crg-plugin.ts
    error="app.on is not a function"

Affected template: `_opencode_plugin_content()` in `code_review_graph/skills.py`
(all three hooks: `file.edited`, `session.created`, `tool.execute.before`).

Steps to reproduce

the run($, cmd) helper uses
$+""+${cmd}+""+`` — in Bun shell, interpolating a full command string as
the whole template escapes it into ONE executable name and throws (verified).
Even if app.on worked, every `run()` call would silently no-op through the
swallowed catch. Commands must be literal tagged templates.

Expected vs actual behavior

(verified with routing tests):

import type { Plugin } from "@opencode-ai/plugin"

export default (async ({ $ }: { $: any }) => {
  return {
    event: async ({ event }: { event: { type: string } }) => {
      if (event.type === "file.edited") {
        try { await $`code-review-graph update --skip-flows`.quiet() } catch {}
      }
      if (event.type === "session.created") {
        try {
          const result = await $`code-review-graph status`.quiet()
          const output = result.stdout?.toString().trim()
          if (output) console.log("[code-review-graph]", output)
        } catch {}
      }
    },
    "tool.execute.before": async (input: { tool: string; args?: { command?: string } }) => {
      try {
        if (/^git\s+commit/i.test(input?.args?.command ?? "")) {
          const result = await $`code-review-graph detect-changes --brief`.quiet()
          const output = result.stdout?.toString().trim()
          if (output) console.log("[code-review-graph] Pre-commit analysis:\n" + output)
        }
      } catch {}
    },
  }
}) satisfies Plugin

Note: install_opencode_plugin() unconditionally overwrites the file
("If the file already exists it is overwritten"), so hand-fixes get
clobbered by any re-run of install.

Additional context

No response