docs(pi): describe the deadline-sized sandbox, not a fixed hour

Both facts in this paragraph were stale: the lifetime is no longer a single
sub-hour constant (it tracks the run's own remaining execution time), and the
ceiling was justified by E2B's Hobby limit on an account that is on
Professional.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: icecrasher321

apps/docs/content/docs/en/workflows/blocks/pi.mdx

@@ -194,7 +194,7 @@ Create PR runs in a sandbox image with the Pi CLI and git baked in.
 
 1. **Enable sandbox execution.** On self-hosted Sim, set `E2B_ENABLED=true`, `E2B_API_KEY`, `E2B_PI_TEMPLATE_ID` (the Pi template id), and `NEXT_PUBLIC_E2B_ENABLED=true` (this reveals Create PR and Review Code in the UI). Build the template with `bun run apps/sim/scripts/build-pi-e2b-template.ts`. These modes stay hidden until `NEXT_PUBLIC_E2B_ENABLED` is set.
 
-   Sim asks E2B to keep a Pi sandbox alive for just under an hour, because E2B caps a sandbox at 1 hour on Hobby accounts (24 hours on Pro) and rejects a longer one outright. `PI_SANDBOX_LIFETIME_MS` may lower that ceiling but has a **31-minute minimum**; lower values are raised to the minimum. A run that outlives the sandbox loses its work before the push, and an orphaned sandbox — one whose Sim process died mid-run — bills until the lifetime expires. Babysit Mode uses a second sequential sandbox after the creation sandbox has been destroyed; it is billed while polling checks and reviews. Daytona remains unchanged because its auto-stop setting is inactivity-based rather than an absolute lifetime.
+   Sim sizes each Pi sandbox to **the execution's own remaining time**, so a run never holds a sandbox longer than the platform would let it run. The ceiling when there is no deadline to narrow to is the longest execution any plan permits (90 minutes); E2B rejects a create above the session length its plan allows, which is 1 hour on Hobby and 24 hours on Professional. `PI_SANDBOX_LIFETIME_MS` may lower that ceiling but has a **31-minute minimum**; lower values are raised to the minimum. A run that outlives the sandbox loses its work before the push, and an orphaned sandbox — one whose Sim process died mid-run — bills until the lifetime expires, which is why that lifetime tracks the deadline. Babysit Mode uses a second sequential sandbox after the creation sandbox has been destroyed; it is billed while polling checks and reviews. Daytona remains unchanged because its auto-stop setting is inactivity-based rather than an absolute lifetime.
 2. **Bring your own model key.** Set the provider API key in the block's API Key field, or store it in **Settings → BYOK** when the provider supports workspace BYOK.
 3. **Create a GitHub token** with permission to clone, push, and open a PR:
    - *Fine-grained:* select the repo, then **Contents: Read and write** + **Pull requests: Read and write**.