* feat(e2b-sandbox): make mount upload deadline configurable
Replace the hardcoded 120-second mount upload deadline with a
configurable `mount_upload_deadline_seconds` key read from
SandboxConfig (extra=allow). The value is validated: zero and
negative inputs are clamped to 1 second. Omitting the key
preserves the existing 120-second default.
This addresses the follow-up from PR #4842 review: operators
with large mounts or slow networks can now size the deadline to
their deployment without changing code.
* fix(e2b-sandbox): address review feedback on configurable deadline
- Remove import-time default capture from _mount_deadline_reason()
and _MountUploadBudget.deadline_seconds to prevent silent drift.
- Add warning log when mount_upload_deadline_seconds is clamped to 1
(was silent before).
- Update AGENTS.md E2B Mount Uploads section: deadline is now
configurable, not fixed 120.
- Add mount_upload_deadline_seconds to YAML examples in provider
docstring and __init__.py.
- Add config-path test that exercises SandboxConfig -> _load_config ->
_apply_mounts end-to-end.
* fix(e2b-sandbox-provider): handle non-numeric mount_upload_deadline_seconds
Guard _resolve_mount_upload_deadline against None, non-numeric strings,
and other invalid values. None returns the default; non-numeric strings
like '120s' or 'abc' log a warning and fall back to the 120-second
default instead of crashing provider init with TypeError/ValueError.
Extend the parametrized clamp test with None, suffix, and alpha cases,
and add a warning assertion. Update CONFIGURATION.md with the new
mount_upload_deadline_seconds key and its behavior.
* fix(sandbox): handle infinite mount deadline