fix: SDK API compatibility, port range, and empty string form handling

[hjpinheiro]

Summary

Three bug fixes that prevent the plugin from working correctly with the current Daytona SDK (0.187.0).

1. Credential validation broken — list() API change

The Daytona SDK changed the list() signature:

# Old (broken with SDK ≥0.187.0):
daytona.list(limit=1)  # TypeError: unexpected keyword argument "limit"

# Fixed:
list(daytona.list(query=ListSandboxesQuery(limit=1)))

This causes credential validation to fail on every new install.

2. Unpinned SDK dependency

daytona>=0.1.0 has no upper bound and silently installs incompatible SDK versions. Pinned to >=0.187.0,<0.188.0 to match the tested API surface.

3. Port range restriction (3000–9999 → 1–65535)

get_preview_url rejected valid ports outside the arbitrary 3000–9999 range, blocking common services (port 80, 443, etc.).

4. Empty string form values crash create_sandbox

Dify form inputs send empty strings ("") when fields are left blank, not None. The previous is None checks missed this, causing ValueError: invalid literal for int() with base 10: "" when cpu, memory, disk, or auto_stop_interval were empty.

Testing

• YAML files validated with yaml.safe_load()
• Python files validated with py_compile
• SDK list() signature verified against installed daytona==0.187.0

Files changed

File	Change
provider/daytona.py	list(limit=1) → list(query=ListSandboxesQuery(limit=1))
requirements.txt	daytona>=0.1.0 → daytona>=0.187.0,<0.188.0
pyproject.toml	Same version pin
tools/get_preview_url.py	Port range 3000-9999 → 1-65535
tools/get_preview_url.yaml	Updated llm_description port range
tools/create_sandbox.py	Handle "" same as None for numeric params