Harden remote sandbox runtime probes, timeouts, and installs (#5685)

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies
> - Each agent runs inside a sandbox environment so its CLI is isolated
from the host
> - Sandbox-backed adapter runs go through a small set of shared helpers
— `ensureAdapterExecutionTargetCommandResolvable`, the sandbox callback
bridge runner, and per-adapter `SANDBOX_INSTALL_COMMAND` strings
> - When standing up new sandbox provider plugins, the existing helpers
timed out, missed install fallbacks, or leaned on assumptions that only
held for E2B
> - Local adapters (`claude-local`, `codex-local`, `gemini-local`,
`opencode-local`) needed slightly hardened probes so they could install
themselves and validate inside *any* remote sandbox transport, not just
E2B
> - This pull request bundles those runtime fixes so future sandbox
provider plugins inherit a working baseline
> - The benefit is that adding a new sandbox provider plugin no longer
requires touching adapter-utils or each local-adapter probe — the
supporting infra is already correct

## What Changed

- `packages/adapter-utils/src/execution-target.ts`: introduce
`DEFAULT_REMOTE_SANDBOX_ADAPTER_TIMEOUT_SEC = 1800` and
`resolveAdapterExecutionTargetTimeoutSec(...)`. Local and SSH adapters
keep the historical "0 means no adapter timeout" behavior;
sandbox-backed runs without an explicit `timeoutSec` get an explicit
30-minute default so remote installs and warm-up don't time out at the
per-RPC default. Plumbed `timeoutSec` through
`ensureAdapterExecutionTargetCommandResolvable` so install probes inside
a sandbox honor adapter-level overrides instead of the bridge's 5-minute
default.
- `packages/adapters/opencode-local/src/index.ts`: switch
`SANDBOX_INSTALL_COMMAND` from `npm install -g opencode-ai` to `curl
-fsSL https://opencode.ai/install | bash`. The npm package reifies four
large prebuilt-binary subpackages in parallel even though only one
matches the host arch; on bandwidth-constrained sandboxes that blew
through the 240s install budget. The official installer fetches one
arch-specific binary and adds `$HOME/.opencode/bin` to PATH via
`~/.bashrc`, which the sandbox-callback-bridge login-shell script
already sources.
- `packages/adapters/{claude,codex,gemini,opencode}-local/`: harden
remote-target probes — pass `--skip-git-repo-check` for Codex when
probing outside a repo, normalize permission flags for Claude, and add
`*.remote.test.ts` coverage that exercises the remote-sandbox path
explicitly for each adapter.
- `packages/adapter-utils/src/sandbox-install-command.{ts,test.ts}`
(new): add `buildSandboxNpmInstallCommand` helper.
`server/src/adapters/registry.ts` + new
`server/src/__tests__/adapter-registry.test.ts`: wire adapter install
commands so they fall back to a writable `$HOME/.local` prefix when
global install isn't available.
- `server/src/__tests__/plugin-worker-manager.test.ts` + new
`server/src/__tests__/fixtures/plugin-worker-delayed.cjs`: pin per-call
timeout overrides so plugin worker exec calls honor the caller's timeout
instead of the worker's default.

## Verification

- `pnpm typecheck`
- `pnpm exec vitest run --no-coverage
packages/adapter-utils/src/execution-target-sandbox.test.ts
packages/adapter-utils/src/sandbox-install-command.test.ts`
- `pnpm exec vitest run --no-coverage
server/src/__tests__/plugin-worker-manager.test.ts
server/src/__tests__/adapter-registry.test.ts
server/src/__tests__/claude-local-adapter-environment.test.ts
server/src/__tests__/claude-local-execute.test.ts
server/src/__tests__/gemini-local-adapter-environment.test.ts`
- `pnpm exec vitest run --no-coverage
packages/adapters/codex-local/src/server/test.remote.test.ts
packages/adapters/opencode-local/src/server/test.remote.test.ts
packages/adapters/codex-local/src/server/codex-args.test.ts
packages/adapters/codex-local/src/server/execute.remote.test.ts
packages/adapters/gemini-local/src/server/execute.remote.test.ts`

All passing locally.

## Risks

- Touches shared `adapter-utils` and several `*-local` adapters. The
30-minute default applies only when both (a) the target is
`remote+sandbox` and (b) no `timeoutSec` is configured — local + SSH
paths are unchanged. New test coverage was added alongside each behavior
change to pin the contracts.
- Switching OpenCode's install command to the official installer is a
behavior change for any operator running OpenCode inside a remote
sandbox. Local installs are unaffected (the `SANDBOX_INSTALL_COMMAND`
only runs when an adapter is being installed inside a sandbox).
- Low risk overall — no migrations, no API surface change.

## Model Used

- Provider: Anthropic
- Model: Claude Opus 4.7 (1M context)
- Capabilities used: extended reasoning, tool use (Read/Edit/Bash/Grep),
no code execution beyond local repo commands

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [ ] If this change affects the UI, I have included before/after
screenshots — N/A, no UI change
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge

Co-authored-by: Paperclip <noreply@paperclip.ing>

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

@@ -127,7 +127,7 @@ async function prepareCodexHelloProbe(input: {
 
   if (input.probeApiKey) {
     const probeHome = input.targetIsRemote
-      ? `/tmp/paperclip-codex-probe-${input.runId}`
+      ? path.posix.join(input.cwd, ".paperclip-runtime", "codex", `probe-home-${input.runId}`)
       : path.join(os.tmpdir(), `paperclip-codex-probe-${input.runId}`);
     return {
       command: "sh",
@@ -162,6 +162,7 @@ export async function testEnvironment(
   const command = asString(config.command, "codex");
   const target = ctx.executionTarget ?? null;
   const targetIsRemote = target?.kind === "remote";
+  const targetIsSandbox = target?.kind === "remote" && target.transport === "sandbox";
   const cwd = resolveAdapterExecutionTargetCwd(target, asString(config.cwd, ""), process.cwd());
   const targetLabel = targetIsRemote
     ? ctx.environmentName ?? describeAdapterExecutionTarget(target)
@@ -271,7 +272,10 @@ export async function testEnvironment(
         hint: "Use the `codex` CLI command to run the automatic login and installation probe.",
       });
     } else {
-      const execArgs = buildCodexExecArgs({ ...config, fastMode: false });
+      const execArgs = buildCodexExecArgs(
+        { ...config, fastMode: false },
+        { skipGitRepoCheck: targetIsSandbox },
+      );
       const args = execArgs.args;
       if (execArgs.fastModeIgnoredReason) {
         checks.push({
@@ -281,6 +285,14 @@ export async function testEnvironment(
           hint: "Switch the agent model to GPT-5.4 or enter a manual model ID to enable Codex Fast mode.",
         });
       }
+      if (targetIsSandbox) {
+        checks.push({
+          code: "codex_git_repo_check_skipped",
+          level: "info",
+          message: "Added --skip-git-repo-check for sandbox hello probes.",
+          hint: "Codex requires an explicit trust bypass in headless remote sandbox workspaces.",
+        });
+      }
 
       // Codex CLI (>= 0.122) ignores the OPENAI_API_KEY env var and only reads
       // credentials from $CODEX_HOME/auth.json. When we have a key available,