refactor: rebuild as an emblem plugin on nemo-repo-core

Everything that was not about drawing emblems moves out: the columns, the properties tab and the context menu are their own plugins now, and the config, git and cache layers come from nemo-repo-core.

The indicator list stops being hardcoded. Entries that are not one of the three git derived indicators are matched by marker_directory or marker_file, which is how claude_dir now works and how a user adds their own without touching the code.

nemoRepoEmblems.py

@@ -0,0 +1,131 @@
+#!/usr/bin/python3
+"""nemo-repo-emblems: emblem overlays for repository folders in Nemo.
+
+Four indicators ship by default: the folder is a git repository, it holds a
+.claude directory, its working tree is dirty, it has commits the remote does
+not. Indicators are declared in the config file, so extra ones can be added
+without touching this file.
+
+Requires nemo-repo-core: https://github.com/dualfroz/nemo-repo-core
+"""
+
+import importlib.util
+import os
+import sys
+
+
+def _ensureCoreOnPath():
+    if importlib.util.find_spec("nemoRepoCore") is not None:
+        return
+    dataHome = os.environ.get("XDG_DATA_HOME") or os.path.expanduser("~/.local/share")
+    dataDirs = (os.environ.get("XDG_DATA_DIRS") or "/usr/local/share:/usr/share").split(":")
+    for base in [dataHome] + dataDirs:
+        candidate = os.path.join(base, "nemo-repo-core")
+        if os.path.isdir(os.path.join(candidate, "nemoRepoCore")):
+            sys.path.insert(0, candidate)
+            return
+
+
+_ensureCoreOnPath()
+
+import gi
+
+gi.require_version("Nemo", "3.0")
+from gi.repository import GObject, Nemo
+
+from nemoRepoCore import (coreConfig, findRepoRoot, hasMarkerDirectory,
+                          localDirectoryPath, pluginLogger, repoCache,
+                          requireCore)
+
+requireCore("1.0.0")
+
+logger = pluginLogger("emblems")
+
+gitIndicators = ("git_repo", "uncommitted_changes", "unpushed_commits")
+
+pluginDefaults = {
+    "indicators": {
+        "git_repo": {
+            "enabled": True,
+            "emblem": "emblem-repo-git",
+            "description": "Folder contains a .git directory (or worktree file)",
+        },
+        "claude_dir": {
+            "enabled": True,
+            "emblem": "emblem-repo-claude",
+            "marker_directory": ".claude",
+            "description": "Folder contains a .claude directory",
+        },
+        "uncommitted_changes": {
+            "enabled": True,
+            "emblem": "emblem-repo-dirty",
+            "description": "git status shows staged, unstaged or untracked changes",
+        },
+        "unpushed_commits": {
+            "enabled": True,
+            "emblem": "emblem-repo-unpushed",
+            "description": "Branch is ahead of its upstream, or has no upstream",
+        },
+    },
+}
+
+coreConfig.registerDefaults(pluginDefaults)
+
+
+def _enabledIndicators():
+    """Config entries that are switched on and name an emblem, by key."""
+    active = {}
+    for key, entry in coreConfig.section("indicators").items():
+        if not isinstance(entry, dict) or not entry.get("enabled"):
+            continue
+        if entry.get("emblem"):
+            active[key] = entry
+    return active
+
+
+def _markerMatches(path, entry):
+    markerDirectory = entry.get("marker_directory")
+    if markerDirectory and hasMarkerDirectory(path, markerDirectory):
+        return True
+    markerFile = entry.get("marker_file")
+    return bool(markerFile) and os.path.isfile(os.path.join(path, markerFile))
+
+
+class RepoEmblemProvider(GObject.GObject, Nemo.InfoProvider,
+                         Nemo.NameAndDescProvider):
+
+    def update_file_info(self, file):
+        path = localDirectoryPath(file)
+        if path is None:
+            return
+
+        active = _enabledIndicators()
+        for key, entry in active.items():
+            if key not in gitIndicators and _markerMatches(path, entry):
+                file.add_emblem(entry["emblem"])
+
+        repoRoot = findRepoRoot(path)
+        if repoRoot is None:
+            return
+
+        if "git_repo" in active:
+            file.add_emblem(active["git_repo"]["emblem"])
+
+        wantsDirty = "uncommitted_changes" in active
+        wantsUnpushed = "unpushed_commits" in active
+        if not (wantsDirty or wantsUnpushed):
+            return
+
+        repoCache.registerFileObject(repoRoot, file)
+        info = repoCache.get(repoRoot)
+        if info.error:
+            return
+
+        if wantsDirty and info.dirty:
+            file.add_emblem(active["uncommitted_changes"]["emblem"])
+        if wantsUnpushed and info.unpushed:
+            file.add_emblem(active["unpushed_commits"]["emblem"])
+
+    def get_name_and_desc(self):
+        return ["nemo-repo-emblems:::Emblem overlays for git repositories "
+                "and marker directories"]