User config file for keybindings and comment file path

[carsonjones]

Summary

Adds ~/.config/comview/config.json (respects $XDG_CONFIG_HOME) for user-local settings.

• comment_file — override the default .comview/comments.json path with any absolute path
• keybindings — remap named actions to custom key strings using vaxis MatchString format

Configurable actions

cursor_down, cursor_up, cursor_left, cursor_right, half_page_down, half_page_up, cursor_bottom, next_commit, prev_commit, toggle_layout, search, next_result, prev_result, open_editor, yank, fuzzy_next, fuzzy_prev

Key string format

Uses vaxis MatchString format — modifier names joined by +, then the key name or character. Examples: "ctrl+d", "shift+j", "Page_Down", "super+c", "j".

A non-empty list in config replaces the defaults for that action.

Example config

{
  "comment_file": "~/.local/share/comview/comments.json",
  "keybindings": {
    "half_page_down": ["ctrl+d", "ctrl+f", "Page_Down"],
    "half_page_up":   ["ctrl+u", "ctrl+b", "Page_Up"],
    "fuzzy_next":     ["Down", "ctrl+n"],
    "fuzzy_prev":     ["Up",   "ctrl+p"]
  }
}

Implementation notes

• Config is loaded once at startup via loadConfig() in tui/config.go
• Bindings.Matches falls back to defaultKeybindings when no user config is present, so zero-value Bindings works correctly (no init required in tests)
• Existing behavior is fully preserved when no config file exists

🤖 Generated with Claude Code

[rockorager]

Reviewed locally. go test ./... passes on the PR branch, and a local merge with current origin/main was clean + tests passed.

Two small issues I noticed:

1. loadConfig() silently ignores config read errors and JSON unmarshal errors, so malformed config or a permission problem falls back to defaults without telling the user. Since this config can change the comment storage path, a typo could unexpectedly make comments load/save from the default path. I’d prefer returning an error from config loading and surfacing it from Run.

2. The PR description example uses "comment_file": "~/.local/share/comview/comments.json", but the implementation passes the string directly to review.LoadFile/SaveFile; Go won’t expand ~, so that would be treated as a relative ./~/.local/... path. Either expand leading ~ or update the docs/example to require a real absolute path.

No blockers beyond those UX/config correctness concerns.

[rockorager]

Update: I missed the new mise.toml because this PR branch predates those commits. I tested a local merge with current origin/main and ran mise run check; it passes (check-multiline-functions, gofumpt, golangci-lint run ./..., and go test ./...).

[rockorager]

Heh, those were ai generated. No worries about them - i'll push a follow up commit to expand "~"

Thanks!