Add tree-grouped alias display in moshmux list

[plinde]

Summary

• Aliases sharing the same directory are now visually grouped with ASCII tree connectors (├─/└─) in moshmux list
• Canonical alias is auto-detected: alias referenced as session by others > alias where name == session > alphabetically first
• Children sharing the parent's session have redundant status/time columns blanked for cleaner output
• New --no-tree flag disables grouping for flat output

Example output

ALIAS          STATUS     LAST ACTIVE  CONFIGURED
minecraft      detached   13h ago      ~/workspace/minecraft-bedrock
└─ * mc
hpi            attached   1d ago       ~/workspace/screaming-into-the-void
└─ * void
moshmux        detached   14h ago      ~/workspace/moshmux
└─ mux         detached   2m ago       ~/workspace/moshmux

Test plan

• moshmux list --no-tui — tree-grouped output with ASCII connectors
• moshmux list --no-tui --no-tree — flat output (original behavior)
• moshmux list — TUI mode with tree grouping and 2s refresh
• moshmux upgrade — still works (uses buildRows directly)
• Build succeeds with no errors

🤖 Generated with Claude Code