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/index.ts

@@ -37,4 +37,7 @@ Notes:
 - Paperclip requires an explicit \`model\` value for \`opencode_local\` agents.
 - Runs are executed with: opencode run --format json ...
 - Sessions are resumed with --session when stored session cwd matches current cwd.
+- The adapter sets OPENCODE_DISABLE_PROJECT_CONFIG=true to prevent OpenCode from \
+  writing an opencode.json config file into the project working directory. Model \
+  selection is passed via the --model CLI flag instead.
 `;

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");