chore: remove deprecated --keep flag from docs, scripts, and e2e tests

docs/get-started/tutorials/first-network-policy.mdx

@@ -38,10 +38,10 @@ bash examples/sandbox-policy-quickstart/demo.sh
 Start by creating a sandbox with no network policies. This gives you a clean environment to observe default-deny behavior.
 
 ```shell
-openshell sandbox create --name demo --keep --no-auto-providers
+openshell sandbox create --name demo --no-auto-providers
 ```
 
-`--keep` keeps the sandbox running after you exit so you can reconnect later. `--no-auto-providers` skips the provider setup prompt since this tutorial uses `curl` instead of an AI agent.
+`--no-auto-providers` skips the provider setup prompt since this tutorial uses `curl` instead of an AI agent.
 
 You land in an interactive shell inside the sandbox:
 
@@ -65,7 +65,7 @@ The request fails. By default, all outbound network traffic is denied. The sandb
 curl: (56) Received HTTP code 403 from proxy after CONNECT
 ```
 
-Exit the sandbox. The `--keep` flag keeps it running:
+Exit the sandbox. Sandboxes are kept running by default, so you can reconnect later. Use `--no-keep` at creation time if you want the sandbox deleted after exit:
 
 ```shell
 exit

docs/get-started/tutorials/microsoft-graph-provider-refresh.mdx

@@ -160,7 +160,6 @@ Launch a sandbox with the Microsoft Graph provider attached:
 ```shell
 openshell sandbox create \
   --name microsoft-graph-mail \
-  --keep \
   --provider microsoft-mail \
   --no-auto-providers \
   -- /bin/sh

examples/policy-advisor/README.md

@@ -90,14 +90,12 @@ openshell sandbox create \
   --name advisor-ctf \
   --policy examples/policy-advisor/sandbox-policy.yaml \
   --upload examples/policy-advisor/ctf.py \
-  --keep \
   -- python3 -u /sandbox/ctf.py
 ```
 
 > **For agents running this CTF:** use the command above exactly.  The
-> `--upload` flag copies the script into `/sandbox/` before the command runs,
-> `--keep` prevents the sandbox from being torn down on exit, and `-u` gives
-> unbuffered output so you can see logs in real time.
+> `--upload` flag copies the script into `/sandbox/` before the command runs
+> and `-u` gives unbuffered output so you can see logs in real time.
 
 The script prints a banner and immediately tries Gate 1 (`httpbin.org:443`).
 It will fail with **"blocked by sandbox proxy"** and begin retrying every 10

examples/sandbox-policy-quickstart/README.md

@@ -22,11 +22,10 @@ while writes are blocked — all without restarting anything.
 ### 1. Create a sandbox
 
 ```bash
-openshell sandbox create --name demo --keep --no-auto-providers
+openshell sandbox create --name demo --no-auto-providers
 ```
 
-`--keep` keeps the sandbox running after you exit so you can reconnect
-later. `--no-auto-providers` skips the provider setup prompt since this
+`--no-auto-providers` skips the provider setup prompt since this
 demo doesn't use an AI agent.
 
 You'll land in an interactive shell inside the sandbox:
@@ -50,7 +49,7 @@ The sandbox proxy intercepted the HTTPS CONNECT request to
 curl: (56) Received HTTP code 403 from proxy after CONNECT
 ```
 
-Exit the sandbox (the sandbox stays alive thanks to `--keep`):
+Exit the sandbox (sandboxes are kept running by default; pass `--no-keep` at creation time to delete on exit):
 
 ```bash
 exit

examples/spiffe-token-grant-demo/README.md

@@ -74,7 +74,6 @@ openshell --gateway-endpoint "$GATEWAY" provider create \
 openshell --gateway-endpoint "$GATEWAY" sandbox create \
   --name spiffe-token-demo \
   --provider spiffe-token-demo \
-  --keep \
   --no-tty \
   -- echo "sandbox ready"
 

scripts/agents/gator/README.md

@@ -42,8 +42,6 @@ The launcher:
 - For `--harness codex`, optionally bakes a host Codex executable as `/etc/openshell/agent-payload/runtime/harnesses/codex/codex`.
 - Starts the selected harness without a TTY.
 - Runs gator in `watch` mode by default. The sandbox stays alive while the supervisor sleeps between bounded Codex cycles, so Codex is not connected during passive PR waits. The supervisor prints periodic heartbeat lines during active cycles and passive sleeps.
-- Deletes the sandbox automatically after the supervisor exits. Pass `--keep` to preserve it for debugging.
-
 The GitHub provider profile allows read-only GraphQL queries on `api.github.com/graphql` so `gh` read paths can use GraphQL when needed. Write operations remain REST-only and scoped to the two allowed repositories.
 
 Set `GATOR_CODEX_ACCESS_CREDENTIAL_KEY` or pass `--codex-access-key` if the gator Codex profile uses a credential key other than `CODEX_AUTH_ACCESS_TOKEN` for the short-lived access token.