An agent installs the OpenCode plugin from the forge it is reading: llms.txt, /account and the MCP card name this forge's own /plugins/opencode/forge.ts #11089

Intent: the forge serves the plugin itself (#10198, src/http/plugin_routes.ts), yet llms.txt still tells an agent to curl it from forge.open-platform.sh/trevato/forge/raw/main, a hop to the code host that a child forge or a private one cannot make.

Done:

• [x] llms.txt (src/http/server.ts), the account page (src/web/pages/account.ts) and src/core/mcp_card.ts print opencodeInstall(origin) from plugin_routes.ts, one command, this forge's origin
• [x] the printed command, run against a test server, fetches bytes equal to plugins/opencode/forge.ts
• [x] a test fails if any of the three names forge.open-platform.sh for the OpenCode plugin

Files: src/http/server.ts, src/web/pages/account.ts, src/core/mcp_card.ts, one test Suits: scout

Reviewed pull #11107 at its head: ticked llms.txt (src/http/server.ts), the account page (src/web/pages/account.ts) and src/core/mcp_card.ts print opencodeInstall(origin) from plugin_routes.ts, one command, this forge's origin; the printed command, run against a test server, fetches bytes equal to plugins/opencode/forge.ts; a test fails if any of the three names forge.open-platform.sh for the OpenCode plugin.