fix(background-agent): inherit parent session directory for background tasks

Background tasks were defaulting to $HOME instead of the parent session's
working directory. This caused background agents to scan the entire home
directory instead of the project directory, leading to:
- High CPU/memory load from scanning unrelated files
- Permission errors on system directories
- Task failures and timeouts

The fix retrieves the parent session's directory before creating a new
background session and passes it via the query.directory parameter.

Files modified:
- manager.ts: Look up parent session directory in launch()
- call-omo-agent/tools.ts: Same fix for sync mode
- look-at/tools.ts: Same fix for look_at tool
- sisyphus-task/tools.ts: Same fix + interface update for directory prop
- index.ts: Pass directory to sisyphusTask factory

src/tools/look-at/tools.ts

@@ -65,11 +65,19 @@ Be thorough on what was requested, concise on everything else.
 If the requested information is not found, clearly state what is missing.`
 
       log(`[look_at] Creating session with parent: ${toolContext.sessionID}`)
+      const parentSession = await ctx.client.session.get({
+        path: { id: toolContext.sessionID },
+      }).catch(() => null)
+      const parentDirectory = parentSession?.data?.directory ?? ctx.directory
+
       const createResult = await ctx.client.session.create({
         body: {
           parentID: toolContext.sessionID,
           title: `look_at: ${args.goal.substring(0, 50)}`,
         },
+        query: {
+          directory: parentDirectory,
+        },
       })
 
       if (createResult.error) {