Summary

Add comprehensive dependency management to the runtimed-py Python bindings, enabling agents to programmatically manage notebook environments just like the frontend does.

New capabilities:

• Get/add/remove UV and Conda dependencies from notebook metadata
• Restart kernel with new environment configuration
• Hot-install UV packages via sync_environment() (UV additions only, no restart needed)

Changes

New Output Type

• SyncEnvironmentResult: Represents outcome of environment sync operation with success, synced_packages, error, and needs_restart fields

New Methods on Session and AsyncSession (8 methods each)

1. get_uv_dependencies() - Get current UV dependency list
2. add_uv_dependency(package) - Add UV dependency (exact match), returns updated list
3. remove_uv_dependency(package) - Remove UV dependency (exact match), returns updated list
4. get_conda_dependencies() - Get current Conda dependency list
5. add_conda_dependency(package) - Add Conda dependency (exact match), returns updated list
6. remove_conda_dependency(package) - Remove Conda dependency (exact match), returns updated list
7. restart_kernel(wait_for_ready=true) - Shutdown kernel and start new one with "auto" environment detection (picks up inline deps)
8. sync_environment() - Hot-install UV packages via daemon sync protocol, returns SyncEnvironmentResult

Implementation Details

Dependency management:

• Reads/writes notebook metadata via the daemon's metadata system
• Dependencies stored in metadata.runt.uv.dependencies and metadata.runt.conda.dependencies
• Uses exact string matching for add/remove (accepts full PEP 508 specs from user)

Kernel restart:

• Calls shutdown_kernel() then start_kernel() with "auto" env_source
• "auto" mode triggers daemon environment detection to pick up inline deps
• Optionally waits for kernel to reach "idle" status (30s timeout)

Sync environment:

• Implements daemon protocol for hot-installing UV packages without restart
• Returns success/failure with detailed error and needs_restart flag
• Only works for UV inline additions (removals/conda require full restart)

Dependencies

Added notebook-doc crate for NotebookMetadataSnapshot types needed to read/write metadata.

API Example

from runtimed import Session

# Add dependencies and restart
with Session() as session:
    session.start_kernel()
    session.add_uv_dependency("pandas>=2.0")
    session.add_uv_dependency("matplotlib")
    session.restart_kernel()
    result = session.run("import pandas; import matplotlib")

# Hot-install (UV only, no restart)
with Session() as session:
    session.start_kernel()
    session.add_uv_dependency("requests")
    sync_result = session.sync_environment()
    if sync_result.success:
        session.run("import requests")
    elif sync_result.needs_restart:
        session.restart_kernel()

Test Plan

• Code compiles with cargo check -p runtimed-py
• Code is formatted with cargo fmt -p runtimed-py
• Manual verification in Python: call get/add/remove methods and verify metadata changes
• Manual verification: restart_kernel() shuts down and starts new kernel
• Manual verification: sync_environment() works for UV additions