Move registry cache to XDG cache directory

CONTRIBUTING.md

@@ -29,7 +29,7 @@ make check    # fmt, vet, lint, test
 |---------|------|---------|
 | `cmd/todo` | CLI command tree (`add`, `init`, `list`, `pickup`, `release`, `remove`, `detail`, `complete`, `reopen`, `bump`, `clear`, `doctor`), flag parsing, all terminal I/O | everything below |
 | `internal/todo` | domain logic: task model, Markdown parse/serialize, ID allocation, filtering, note disposition | `internal/fs`, `internal/git`, `park/schema` |
-| `internal/registry` | machine-local cache of tracked repo folders (`~/.config/.todocache`) | stdlib only |
+| `internal/registry` | machine-local cache of tracked repo folders (`$XDG_CACHE_HOME/todo/registry.json`, falling back to `~/.cache/todo/registry.json`) | stdlib only |
 | `internal/git` | git CLI helpers: repo root, remote URL, remote parsing | stdlib only |
 | `internal/fs` | filesystem helpers (exists check) | stdlib only |
 
@@ -74,6 +74,6 @@ Control flow: per-repo commands resolve the repo root through `requireRepoConfig
 ## Implementation notes
 
 - The only external dependencies are `urfave/cli/v3` (plus `urfave/cli-validation`) and the public `github.com/polymorcodeus/park/schema` package, which supplies the record frontmatter contract and render helpers. Keep `internal/*` free of new dependencies where stdlib will do.
-- The registry path defaults to `~/.config/.todocache` and is overridable via `TODO_REGISTRY`.
+- The registry path defaults to `$XDG_CACHE_HOME/todo/registry.json` (or `~/.cache/todo/registry.json`) and is overridable via `TODO_REGISTRY`.
 - Version is dual-sourced: the embedded `VERSION` file serves local and `go install` builds, while `main.version`/`main.buildTime` ldflags (set by GoReleaser, and by the Makefile for `make build`) win when present.
 - `AGENTS.md` is a private, symlinked file and is not part of this repository. Contributor-facing context belongs in this file and in `README.md`.

README.md

@@ -123,7 +123,7 @@ Status is `[ ]` open, `[o]` in progress, `[x]` done. `claimed:` records when a t
 
 ## Registry
 
-Every `todo init` registers the repo in a machine-local JSON cache at `~/.config/.todocache`. The registry stores the absolute repo path, project name, git remote URL, parsed host/owner, and a `last_seen` timestamp. `todo list --all` and `todo doctor` use this cache to operate across tracked folders without `cd`ing.
+Every `todo init` registers the repo in a machine-local JSON cache at `$XDG_CACHE_HOME/todo/registry.json` (falling back to `~/.cache/todo/registry.json`). The registry stores the absolute repo path, project name, git remote URL, parsed host/owner, and a `last_seen` timestamp. `todo list --all` and `todo doctor` use this cache to operate across tracked folders without `cd`ing.
 
 ## Note disposition
 

VERSION

@@ -1 +1 @@
-v1.0.3
+v1.0.4

cmd/todo/cli_test.go

@@ -23,7 +23,7 @@ func setupGitRepo(t *testing.T) string {
 		t.Fatalf("git init: %v", err)
 	}
 	t.Chdir(dir)
-	t.Setenv("TODO_REGISTRY", filepath.Join(dir, ".todocache"))
+	t.Setenv("TODO_REGISTRY", filepath.Join(dir, "registry.json"))
 	return dir
 }
 

internal/registry/registry.go

@@ -22,13 +22,17 @@ type Entry struct {
 	LastSeen string `json:"last_seen"`
 }
 
-// DefaultPath returns the default registry file path: ~/.config/.todocache.
+// DefaultPath returns the default registry file path:
+// $XDG_CACHE_HOME/todo/registry.json, or ~/.cache/todo/registry.json.
 func DefaultPath() string {
+	if cacheHome := os.Getenv("XDG_CACHE_HOME"); cacheHome != "" {
+		return filepath.Join(cacheHome, "todo", "registry.json")
+	}
 	home, err := os.UserHomeDir()
 	if err != nil {
-		return ".todocache"
+		return "todo-registry.json"
 	}
-	return filepath.Join(home, ".config", ".todocache")
+	return filepath.Join(home, ".cache", "todo", "registry.json")
 }
 
 // Load reads the registry from path. A missing file is treated as an empty

internal/registry/registry_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func TestLoadMissingReturnsEmpty(t *testing.T) {
-	path := filepath.Join(t.TempDir(), "missing", ".todocache")
+	path := filepath.Join(t.TempDir(), "missing", "registry.json")
 	entries, err := Load(path)
 	if err != nil {
 		t.Fatalf("Load missing: %v", err)
@@ -18,7 +18,7 @@ func TestLoadMissingReturnsEmpty(t *testing.T) {
 }
 
 func TestSaveAndLoad(t *testing.T) {
-	path := filepath.Join(t.TempDir(), ".todocache")
+	path := filepath.Join(t.TempDir(), "registry.json")
 	want := []Entry{
 		{Path: "/code/foo", Project: "foo", Repo: "git@example.com:org/foo", LastSeen: "2026-09-01T00:00:00Z"},
 	}