feat(ui): session skills registry tab + per-level selectors

src/ClaudeDo.Localization/locales/en.json

@@ -9,6 +9,7 @@
     "tabWorktrees": "Worktrees",
     "tabFiles": "Files",
     "tabPrime": "Prime Claude",
+    "tabSkills": "Skills",
     "general": {
       "defaultInstructions": "Default instructions",
       "defaultInstructionsPlaceholder": "Baseline instructions applied to every task",
@@ -25,7 +26,9 @@
       "weekdayWednesday": "Wednesday",
       "weekdayThursday": "Thursday",
       "weekdayFriday": "Friday",
-      "weekdaySaturday": "Saturday"
+      "weekdaySaturday": "Saturday",
+      "sessionSkills": "Session skills",
+      "sessionSkillsHint": "Applied to every task. Combines with list- and task-level selections."
     },
     "worktrees": {
       "strategy": "Strategy",
@@ -95,7 +98,17 @@
       "systemPrompt": "System prompt (appended)",
       "promptPrepended": "Prepended automatically:",
       "agentFile": "Agent file",
-      "browse": "Browse..."
+      "browse": "Browse...",
+      "sessionSkills": "Session skills",
+      "sessionSkillsHint": "Combines additively with global (and list) selections."
+    },
+    "skills": {
+      "installSection": "INSTALL",
+      "installUrlPlaceholder": "Git repo URL (owner/repo or full URL)",
+      "installButton": "Install",
+      "installedSection": "INSTALLED",
+      "updateButton": "Update",
+      "removeButton": "Remove"
     }
   },
   "tasks": {
@@ -494,7 +507,7 @@
     "taskStatus": { "idle": "Idle", "queued": "Queued", "running": "Running", "waitingForReview": "Waiting for Review", "waitingForChildren": "Waiting for Improvements", "done": "Done", "failed": "Failed", "cancelled": "Cancelled", "parked": "Parked" },
     "planningBadge": { "active": "PLANNING", "finalized": "PLANNED" },
     "taskRow": { "createdPrefix": "Created {0}", "stepsText": "{0}/{1} steps" },
-    "tasksIsland": { "completedHeader": "COMPLETED", "completedHeaderCount": "COMPLETED · {0}", "runInteractiveFailed": "Run interactively failed: {0}", "planningOpenFailed": "Couldn't open planning session: {0}", "pickUpInTerminalFailed": "Pick up in terminal failed: {0}" },
+    "tasksIsland": { "completedHeader": "COMPLETED", "completedHeaderCount": "COMPLETED · {0}", "runInteractiveFailed": "Run interactively failed: {0}", "planningOpenFailed": "Couldn't open planning session: {0}", "pickUpInTerminalFailed": "Pick up in terminal failed: {0}", "approveFailed": "Approve & merge failed: {0}" },
     "diff": { "loadFailed": "Failed to load diff: {0}", "noChanges": "No changes to show.", "unavailable": "Diff no longer available — commit range incomplete." },
     "planningDiff": { "hubError": "Could not build combined preview (hub error).", "conflict": "Cannot build combined preview: subtask {0} conflicts with an earlier subtask ({1} files)." },
     "merge": { "commitMessage": "Merge task: {0}", "workerOfflineBranches": "Worker offline — cannot list branches.", "loadBranchesFailed": "Failed to load branches: {0}", "merged": "Merged.", "conflict": "Merge conflict — target branch restored. Resolve manually or via Continue, then retry.", "blocked": "Blocked: {0}", "unknownStatus": "Unknown status: {0}", "mergeFailed": "Merge failed: {0}" },
@@ -503,6 +516,7 @@
     "onlineInbox": { "workerOffline": "Worker offline — cannot load config.", "saved": "Config saved.", "saveFailed": "Save failed: {0}", "signedIn": "Signed in successfully.", "signedInNoRole": "Signed in, but this account is missing the 'user' role in Zitadel — online sync will be rejected until the role is granted in the ClaudeDo project.", "signInFailed": "Sign-in failed: {0}", "signedOut": "Signed out.", "signOutFailed": "Sign-out failed: {0}" },
     "weeklyReport": { "invalidRange": "Invalid date range.", "generating": "Generating report…", "error": "Error: {0}" },
     "filesTab": { "workerOffline": "Worker offline.", "noneBundled": "No default agents bundled.", "allPresent": "All default agents already present.", "restored": "Restored {0} default agent(s).", "restoreFailed": "Restore failed: {0}", "openFailed": "Open failed: {0}" },
+    "sessionSkillsTab": { "installed": "Installed: {0}", "installFailed": "Install failed: {0}", "updated": "Updated.", "updateFailed": "Update failed: {0}", "removed": "Removed.", "removeFailed": "Remove failed: {0}" },
     "worktreesTab": { "workerOffline": "Worker offline.", "removed": "Removed {0} worktree(s).", "blocked": "Cannot force-remove: {0} task(s) still running. Cancel them first.", "removedFrom": "Removed {0} worktree(s) from {1} task(s)." },
     "worktreesOverview": { "titleAll": "Worktrees", "titleList": "Worktrees — {0}", "listFallback": "list", "cleanupFailed": "Cleanup failed.", "removed": "Removed {0} worktree(s).", "discardFailed": "Failed to discard worktree.", "keepFailed": "Failed to keep worktree.", "cannotForceRunning": "Cannot force-remove a running task.", "forceRemoveFailed": "Force remove failed.", "batchProgress": "Merging {0}/{1}…", "batchDone": "Merged {0}, {1} need resolution." },
     "listSettings": { "untitled": "Untitled" },