Route only explicit Codex and Claude invocations through smart routing

[lilly-luo]

https://databricks.atlassian.net/browse/AIGTWY-4551

explanation

currently, we are invoking smart routing for /every/ codex and claude command. in reality, we only want to invoke smart routing in 2 cases:

• claude / codex empty - this opens a tui and we route on the first prompt
• claude -- 'hi' / codex -- 'hi' - this opens a tui with 'hi' as the first prompt.;

claude --model xx or codex --model yy should not invoke smart routing.

this PR makes 3 changes so that ucode codex upgrade and ucode codex app-server will work:

1. makes it so that we detect whether there's a prompt ('hi') or if there's no subcommand. if 1 of those is true, we invoke smart routing. otherwise, don't. this ensures things like ucode codex update and ucode codex app-server continue working without having to maintain a hardcoded subcommand list.
2. after (1), we'd get this error on ucode codex update. This is because we, by default, pass the ucode config as argument --profile to all codex commands. however, only codex and codex mcp take --profile. instead, the other commands take --config. so i change codex to pass in --config instead

  Error: --profile only applies to runtime commands and `codex mcp`: `codex`, `codex exec`, `codex review`, `codex resume`, `codex queue`, `codex
  archive`, `codex delete`, `codex unarchive`, `codex fork`, `codex mcp`, `codex sandbox`, and `codex debug prompt-input`.
  ! ucode's `--profile` isn't accepted here (error above). Retrying without it: Codex will resolve /home/lilly.luo/.codex/config.toml and any
  OS-managed settings instead of the ucode profile.

3. even after (2), ucode codex upgrade would return the error below. this is because when we pass --config instead of --profile to codex, we need to serialize the toml file. the serialization logic had to be updated as a result of tomlkit upgrading to 15.0.

finally after 1, 2, and 3 - ucode codex upgrade and ucode codex app-server work.

  ValueError: Inline tables cannot contain a table

test

• ENABLE_SMART_ROUTING_V2=1 SMART_ROUTER_NAME=task_v2 uv run ucode claude
• ENABLE_SMART_ROUTING_V2=1 SMART_ROUTER_NAME=task_v2 uv run ucode codex
• ENABLE_SMART_ROUTING_V2=1 SMART_ROUTER_NAME=task_v2 uv run ucode claude -- 'hi'
• ENABLE_SMART_ROUTING_V2=1 SMART_ROUTER_NAME=task_v2 uv run ucode codex -- 'hi'
• ENABLE_SMART_ROUTING_V2=1 SMART_ROUTER_NAME=task_v2 uv run ucode claude --model system.ai.glm-5-2
• ENABLE_SMART_ROUTING_V2=1 SMART_ROUTER_NAME=task_v2 uv run ucode codex --model system.ai.glm-5-2
• ENABLE_SMART_ROUTING_V2=1 SMART_ROUTER_NAME=task_v2 uv run ucode codex update
• ENABLE_SMART_ROUTING_V2=1 SMART_ROUTER_NAME=task_v2 uv run ucode claude upgrade
• ENABLE_SMART_ROUTING_V2=1 SMART_ROUTER_NAME=task_v2 uv run ucode codex app-server

the below cmds should be unchanged, i tested to ensure no regression

• ENABLE_SMART_ROUTING_V2=0 uv run ucode claude
• ENABLE_SMART_ROUTING_V2=0 uv run ucode codex
• ENABLE_SMART_ROUTING_V2=0 uv run ucode claude --model system.ai.glm-5-2
• ENABLE_SMART_ROUTING_V2=0 uv run ucode codex --model system.ai.glm-5-2
• ENABLE_SMART_ROUTING_V2=0 uv run ucode claude -- 'hi'
• ENABLE_SMART_ROUTING_V2=0 uv run ucode codex -- 'hi'
• ENABLE_SMART_ROUTING_V2=0 uv run ucode codex update
• ENABLE_SMART_ROUTING_V2=0 uv run ucode claude upgrade
• ENABLE_SMART_ROUTING_V2=0 uv run ucode codex app-server

before (confirming i repro'd the issue) :

# version of ucode currently in isaac 
$ uv tool install \
  --default-index https://pypi-proxy.cloud.databricks.com/simple \
  'ucode==0.1.0+f7b4b97'

$ ENABLE_SMART_ROUTING_V2=1 ucode codex update    

╭────────────────────────────────────╮
│ Launching Codex with Unity Gateway │
╰────────────────────────────────────╯
✔ Starting Codex
Error: `--remote ws://127.0.0.1:40091` is only supported for interactive TUI commands, not `codex update`

$ ENABLE_SMART_ROUTING_V2=1 ucode codex app-server

╭────────────────────────────────────╮
│ Launching Codex with Unity Gateway │
╰────────────────────────────────────╯
✔ Starting Codex
Error: `--remote ws://127.0.0.1:32895` is only supported for interactive TUI commands, not `codex app-server`

after (it's fixed)

$ ENABLE_SMART_ROUTING_V2=1 uv run ucode codex update

╭────────────────────────────────────╮
│ Launching Codex with Unity Gateway │
╰────────────────────────────────────╯
✔ Starting Codex

Updating Codex via `bun install -g @openai/codex`...
bun add v1.3.14 (0d9b296a)

installed @openai/codex@0.153.4 with binaries:
 - codex

[1239.00ms] done

🎉 Update ran successfully! Please restart Codex.

$ ENABLE_SMART_ROUTING_V2=1 uv run ucode codex app-server (the 404 is unrelated and still happens with normal codex) 

╭────────────────────────────────────╮
│ Launching Codex with Unity Gateway │
╰────────────────────────────────────╯
✔ Starting Codex
2026-09-04T23:54:14.795144Z ERROR codex_models_manager::manager: failed to refresh available models: unexpected status 404 Not Found: {"error_code":"ENDPOINT_NOT_FOUND","message":"codex/v1/models is not enabled for this workspace."}, url: https://dbc-a5d4177a-49dc.cloud.databricks.com/ai-gateway/codex/v1/models?client_version=0.153.4, request id: fde50f25-d7db-4145-a011-9a49e892670b

[david-siqi-liu]

Do we show some indication in the CLI that smart routing has been enabled, after an user launches a session?

[lilly-luo]

Do we show some indication in the CLI that smart routing has been enabled, after an user launches a session?

yes!