Ask a provider for its models, and let the app update its CLI

The Claude model list was four words in machines.rs, copied into every
machine's config.ron at discovery -- so a model the CLI had gained was
unreachable from the phone, which is how Opus 5.5 came to be invisible.
Every catalog is now read from the provider itself when a picker opens:
Claude Code over its control channel (control_request{subtype:list_models},
the same channel the driver sends set_model down, since the CLI has no
listing command), Codex over app-server, llama.cpp from the GGUFs on its
machine. Echo is the one case config.ron still answers, having nothing to
ask. A row the CLI marks disabled -- a model the installed version is too
old to run -- is dropped rather than offered as a chip that fails.

The reading of each catalog lives in that driver's own module, and
provider_models is one line per driver: core code says which driver to ask
and never what an answer looks like. parse_codex_models moved out for the
same reason.

Beside it, a provider now reports the version of its program and can be
told to update it. The version comes from --version on its own machine,
read from whichever stream carried it but only from a run that exited 0 --
llama-server prints its version to stderr, and so does "command not found".
It is never compared against a latest release, which nothing here can know.
Update runs the driver's own updater, or an updateCommand the config file
names for an install those will not touch; its whole output comes back,
because every install on these machines is package-managed and the
updater's refusal is the sentence worth reading. Nothing on its stdin, so a
password prompt fails rather than hangs.

A catalog that cannot be read no longer fails the whole provider view: that
is exactly the provider somebody came there to update, and refusing the
screen took the version and the Update button away with it.

Verified against a scratch server and on the emulator: the live catalog
(1.06s, disabled row absent), all four providers' versions including the
unknown state, the confirmation and output dialogs, a configured command
returning in 87ms with its stdin closed, and Update correctly disabled for
llama.cpp.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

server/src/usage.rs

@@ -282,10 +282,12 @@ impl UsageProvider for CodexUsage {
             serde_json::json!({"method": "initialized"}),
             serde_json::json!({"id": 2, "method": "account/rateLimits/read"}),
         ];
-        let answer = match self
-            .transport
-            .request_json_blocking(&launch, &initialized, &requests, 2)
-        {
+        let answer = match self.transport.request_json_blocking(
+            &launch,
+            Some(&initialized),
+            &requests,
+            Transport::answer_to(2),
+        ) {
             Ok(answer) => answer,
             Err(err) => {
                 return vec![self.snapshot(
@@ -1105,6 +1107,7 @@ mod tests {
             }),
             providers: vec![crate::config::ProviderConfig {
                 name: "claude-cli".to_string(),
+                update_command: None,
                 kind: DriverKind::ClaudeCli,
                 command: None,
                 models: vec![],
@@ -1171,6 +1174,7 @@ mod tests {
         let mut echo_only = unreachable_machine();
         echo_only.providers = vec![crate::config::ProviderConfig {
             name: "echo".to_string(),
+            update_command: None,
             kind: DriverKind::Echo,
             command: None,
             models: vec![],