Adds the in-TUI surface for the profile system:
- Status bar carries " · profile: <name>" next to the SLM badge when
profile mode is engaged (renders nothing in legacy single-config
installations).
- /profile (no args) shows the active profile and lists available ones.
- /profile <name> switches by re-executing gnoma via syscall.Exec under
--profile <name>. Critical cleanups (quality.json snapshot, SLM
backend Close, session.Close) fire explicitly before exec since
defers don't run after exec replaces the process image. Using
syscall.Exec rather than a child process avoids stacking a process
level on every switch and propagates the new gnoma's exit code
directly to the shell.
- Autocomplete after "/profile " offers configured profile names; the
completion source is threaded from main.go via tui.Config.
Conversation history is not preserved across a switch — profile change
implies different context, different keys, different permission mode,
so a clean reset is the correct semantic.
vikingowl
d84b295da2