feat: Claude Code Monitor — lanes, pipelines and a merged workspace

Internal SmartGift build of a Claude Code monitoring dashboard.

Lanes: a durable unit of parallel agent work, one per working directory,
tracked across session restarts. Managed lanes are git worktrees the
dashboard provisions and can reset or remove behind a three-check destroy
guard and a counted preflight; adopted lanes are directories you already
own and are never destroyable.

Pipelines: a lane moves through pipeline stages. A stage the agent declares
with evidence renders green; a stage inferred from the tool-event stream
renders dashed amber and never counts as done. Detection is forward-only
within a 30-minute window, and never writes the declared stage.

Workspace: one page at /run with a lane grid, the selected lane's pipeline,
and a full Claude console behind a disclosure.

client/src/i18n/locales/en/sessions.json

@@ -0,0 +1,43 @@
+{
+  "title": "Sessions",
+  "searchPlaceholder": "Search sessions...",
+  "filterAll": "All",
+  "filterActive": "Active",
+  "filterWaiting": "Waiting",
+  "filterCompleted": "Completed",
+  "filterError": "Error",
+  "filterAbandoned": "Abandoned",
+  "sessionCount": "{{count}} session recorded",
+  "sessionCount_plural": "{{count}} sessions recorded",
+  "noSessions": "No sessions found",
+  "noSessionsDesc": "Try adjusting your search or filters.",
+  "noSessionsHint": "Start a Claude Code session with hooks installed to begin tracking.",
+  "tableSession": "Session",
+  "tableStatus": "Status",
+  "tableLastActive": "Last Active",
+  "tableDuration": "Duration",
+  "tableAgents": "Agents",
+  "tableCost": "Cost",
+  "tableDirectory": "Directory",
+  "defaultName": "Session ",
+  "detail": {
+    "waitingBanner": {
+      "title": "Waiting for your input",
+      "generic": "Claude Code is paused in this session until you respond in the terminal."
+    },
+    "failedLoad": "Failed to load session",
+    "loading": "Loading session...",
+    "notFound": "Session not found",
+    "backToSessions": "Back to Sessions",
+    "agents": "Agents",
+    "noAgents": "No agents recorded.",
+    "unparented": "Unparented Subagents",
+    "costBreakdown": "Cost Breakdown",
+    "eventTimeline": "Event Timeline",
+    "noEvents": "No events recorded.",
+    "conversation": "Conversation",
+    "timeline": "Timeline ({{shown}}/{{total}})",
+    "transcriptNotFound": "Conversation transcript not found for this agent. The transcript file may be missing or not yet linked."
+  },
+  "remoteSourceBadgeTitle": "Collected from a remote machine"
+}