fix(opencode): prevent opencode.json config pollution in workspace

Set OPENCODE_DISABLE_PROJECT_CONFIG=true in all OpenCode invocations
(execute, model discovery, environment test) to stop the OpenCode CLI
from writing an opencode.json file into the project working directory.
Model selection is already passed via the --model CLI flag.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/adapters/opencode-local/src/server/execute.ts

@@ -128,6 +128,10 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
   const hasExplicitApiKey =
     typeof envConfig.PAPERCLIP_API_KEY === "string" && envConfig.PAPERCLIP_API_KEY.trim().length > 0;
   const env: Record<string, string> = { ...buildPaperclipEnv(agent) };
+  // Prevent OpenCode from writing an opencode.json config file into the
+  // project working directory (which would pollute the git repo).  Model
+  // selection is already handled via the --model CLI flag.
+  env.OPENCODE_DISABLE_PROJECT_CONFIG = "true";
   env.PAPERCLIP_RUN_ID = runId;
   const wakeTaskId =
     (typeof context.taskId === "string" && context.taskId.trim().length > 0 && context.taskId.trim()) ||

packages/adapters/opencode-local/src/server/models.ts

@@ -120,7 +120,8 @@ export async function discoverOpenCodeModels(input: {
     // /etc/passwd entry (e.g. `docker run --user 1234` with a minimal
     // image). Fall back to process.env.HOME.
   }
-  const runtimeEnv = normalizeEnv(ensurePathInEnv({ ...process.env, ...env, ...(resolvedHome ? { HOME: resolvedHome } : {}) }));
+  // Prevent OpenCode from writing an opencode.json into the working directory.
+  const runtimeEnv = normalizeEnv(ensurePathInEnv({ ...process.env, ...env, ...(resolvedHome ? { HOME: resolvedHome } : {}), OPENCODE_DISABLE_PROJECT_CONFIG: "true" }));
 
   const result = await runChildProcess(
     `opencode-models-${Date.now()}-${Math.random().toString(16).slice(2)}`,

packages/adapters/opencode-local/src/server/test.ts

@@ -90,6 +90,8 @@ export async function testEnvironment(
     });
   }
 
+  // Prevent OpenCode from writing an opencode.json into the working directory.
+  env.OPENCODE_DISABLE_PROJECT_CONFIG = "true";
   const runtimeEnv = normalizeEnv(ensurePathInEnv({ ...process.env, ...env }));
 
   const cwdInvalid = checks.some((check) => check.code === "opencode_cwd_invalid");