refactor: replace overloaded surface terminology

packages/sandbox/sandbox-policy/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/sandbox/sandbox-policy/README.md
-README.md: b2512790c5cf5b3a06523cf91b50dd5d288b1522
+README.md: c85420019b490d311360f310c04212ac6cd737d1
 README.zh.md: 58354adf55a55951cad1ea9adb88aea2457c7f7b

packages/sandbox/sandbox-policy/README.md

@@ -13,7 +13,7 @@ Filesystem tools, one-shot bash commands, and terminal sessions may enforce the
 - `mode` — the deployment default `SandboxMode` (`read-only` / `workspace-write` / `danger-full-access`), validated at load. Default `read-only` (fail-safe).
 - `workspaceRoot` — the fallback directory `workspace-write` may write under for agentless calls or sessions without a cwd. Default `process.cwd()`, resolved to its absolute filesystem identity either way. A normal agent call uses its session header's immutable `cwd` instead.
 
-## Surface
+## API
 
 - `ctx.sandboxPolicy.resolve({ session?, mode? })` — resolves one complete per-call policy. An explicit approved mode outranks the session's last `sandbox/mode` event, which outranks `defaultMode`; the session's immutable `cwd` is canonicalized with filesystem semantics before becoming `workspaceRoot`, otherwise the configured fallback applies. Canonicalization precedes lexical normalization so `symlink/..` agrees with process working-directory resolution.
 - `ctx.sandboxPolicy.defaultMode` / `ctx.sandboxPolicy.workspaceRoot` — the deployment default and fallback root used by `resolve()`.