[Feature] Custom Config File Path with Git-Reminder Hint

[Eliezergh]

[Feature] Custom Config File Path with Git-Reminder Hint

Description

Currently, Syndi always reads and writes its configuration to ~/.syndi/config.json. This makes it hard to keep the config in version control, back it up, or move it to a new machine.

This feature adds a single setting that lets users point Syndi at a config.json of their choice — for example, one that already lives inside a dotfiles Git repository. Syndi itself performs no Git operations; the user remains fully in charge of their repository. As a gentle nudge, Syndi will show a notification after saving the config if it detects the file is inside a Git repository, reminding the user to commit and push.

Current Behaviour

• ~/.syndi/config.json is the only supported config location (hardcoded in syndi.py).
• No feedback is given to the user about version-controlling their config.

Proposed Behaviour

1. Custom config path — A new field in ~/.syndi/settings.json (a small, machine-local bootstrap file) lets users specify an alternative path for config.json, e.g. ~/dotfiles/syndi/config.json.
2. Git-repo hint — After every successful config save, if Syndi detects that the config file sits inside a Git repository (i.e. a .git directory exists somewhere in its parent hierarchy), it shows a macOS notification: "Config saved — don't forget to commit and push your changes."
3. Feature is fully opt-in — When no custom path is configured, behaviour is identical to today.

Affected Code

File	What changes
src/core.py	New helper is_inside_git_repo(path) that walks parent dirs looking for .git; save_config() returns a boolean indicating whether the path is Git-tracked
src/syndi.py	Reads optional config_path from ~/.syndi/settings.json at startup; after save_config(), fires a rumps notification if the helper returns True
src/preferences.py	New text field in the Preferences dialog for the custom config file path

Acceptance Criteria

• User can set a custom path for config.json via the Preferences dialog
• Syndi reads from and writes to that custom path instead of the default
• After saving, Syndi shows a notification reminding the user to push if the file is inside a Git repo
• If no custom path is set, all behaviour is identical to today
• Git detection never causes an error — if anything goes wrong it is silently ignored

Migration Path

• First launch after the update: ~/.syndi/settings.json does not exist, so Syndi falls back to ~/.syndi/config.json as usual.
• User opens Preferences, enters a path inside their dotfiles repo, and saves.
• Syndi copies the existing ~/.syndi/config.json to the new location on first use.
• All subsequent reads/writes go to the new path.