feat(dfget): add --daemon option to auto-start dfdaemon

[CormickKneey]

Summary

• Add --daemon flag to dfget that automatically starts a dfdaemon process when one is not already running
• Add --daemon-manager-addr option to specify the manager address for the auto-generated dfdaemon config

Motivation

Currently dfget requires a running dfdaemon process to function. This makes it inconvenient for ad-hoc downloads, development, and testing scenarios where users need to manually ensure dfdaemon is running. The --daemon option allows dfget to handle this automatically.

Behavior

When --daemon is specified, dfget follows this logic:

1. UDS exists and dfdaemon is reachable → use the existing dfdaemon (no change from current behavior)
2. Config file exists → start dfdaemon with the existing config
3. No config file → generate a default config at the default path and start dfdaemon
4. No config file + --daemon-manager-addr specified → generate a default config with the specified manager address
5. Config file exists + --daemon-manager-addr differs from config → warn the user and proceed with the config file address

Usage Examples

# Auto-start dfdaemon with existing config
dfget https://example.com/file.tar.gz -O /tmp/file.tar.gz --daemon

# Auto-start with a specific manager address (generates default config if none exists)
dfget https://example.com/file.tar.gz -O /tmp/file.tar.gz --daemon --daemon-manager-addr=http://manager:65003

# Original behavior is unchanged without --daemon
dfget https://example.com/file.tar.gz -O /tmp/file.tar.gz

Changes

• dragonfly-client/src/bin/dfget/main.rs: Added --daemon and --daemon-manager-addr CLI arguments, ensure_dfdaemon_config(), find_dfdaemon_binary(), start_dfdaemon(), wait_for_dfdaemon_ready() functions, and updated main() with the auto-start branching logic

[codecov]

Codecov Report

❌ Patch coverage is 0.42553% with 234 lines in your changes missing coverage. Please review.
✅ Project coverage is 46.36%. Comparing base (f27be76) to head (adb1b73).

Files with missing lines	Patch %	Lines
dragonfly-client/src/bin/dfget/main.rs	0.42%	234 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1738      +/-   ##
==========================================
- Coverage   46.79%   46.36%   -0.43%     
==========================================
  Files          87       87              
  Lines       24883    25115     +232     
==========================================
+ Hits        11643    11644       +1     
- Misses      13240    13471     +231     

Files with missing lines	Coverage Δ
dragonfly-client/src/bin/dfget/main.rs	42.19% <0.42%> (-7.15%)	⬇️

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