launcher: guided first-run flow, server-owned settings, hook-config reconcile

Release-readiness pass on the launcher, driven by the end state "open it,
create an account, launch the game".

Fixes a silent correctness bug. `openfut.cfg` in the game dir is the only
server address the *game* can see, but it was written only by Setup's deploy
and its "Save & Update hook" button. Changing the server anywhere else left
FIFA connecting to the previous host while every panel in the launcher showed
the new one online. Now:

  - `write_hook_config` reconciles the file from the live config, and runs
    fail-closed before every launch, so the file and the UI cannot disagree at
    the moment it matters;
  - saving Settings pushes the address into the hook immediately;
  - a `hook_config` preflight check reads the file back and warns, naming both
    addresses, instead of leaving the drift invisible;
  - Settings shows the same fact inline, and Save is enabled by drift alone —
    a message saying "Save to update it" beside a disabled button is a dead end.

Account creation is now server-authoritative. `account_sync::discover` POSTs
`/openfut/account/sync` with the persona fields *omitted*, which makes the host
answer with the persona it was started with, its club, and the Core coin
balance. The launcher adopts that answer, so it never invents an identity and
the persona the game authenticates with is by construction the one the server
expects. Claiming is gated on the address being valid, NOT on the health pill:
that pill probes the HTTPS port while this talks to the account port, so gating
on it disabled the button on servers that answer it perfectly well.

UX consolidation:

  - new Welcome ("Get started") tab: three numbered steps — connect, claim an
    account, connect FIFA — each showing live state, ending in the launch CTA;
    a fresh install opens on it and it leaves the nav rail once satisfied;
  - Config renamed Settings, and made the single owner of the server address:
    Setup's duplicate editors (same fields, different save semantics) are now a
    read-only summary with actions;
  - the dashboard offers account creation in place instead of naming a tab, and
    the stale "set the host in the Setup tab" pointers are corrected.

Locks move to parking_lot per project rule (already the convention in
openfut-utas-host and openfut-identity); 47 poisoning unwraps go away.

Verified: 58 tests pass, fmt clean, clippy clean apart from one pre-existing
lint. Driven through the real UI under Xvfb as a fresh install — typed a server,
clicked Create my account, and the config on disk came back with persona
33068179/CAGE claimed from the live host; clicking Save rewrote a stale
`openfut.cfg` from host=10.10.0.99 to host=127.0.0.1.

src/config.rs

@@ -359,10 +359,10 @@ impl LauncherConfig {
     /// this ensures required user configuration is never silently invented.
     pub fn validate_local_services(&self) -> Result<(), String> {
         if self.fifa17_tools_dir.trim().is_empty() {
-            return Err("No FIFA 17 tools dir configured. Set it in the Config tab.".into());
+            return Err("No FIFA 17 tools dir configured. Set it in Settings.".into());
         }
         if self.fifa17_python.trim().is_empty() {
-            return Err("No Python interpreter configured. Set it in the Config tab.".into());
+            return Err("No Python interpreter configured. Set it in Settings.".into());
         }
         Ok(())
     }
@@ -380,7 +380,7 @@ impl LauncherConfig {
         } else if self.game_launch_command.trim().is_empty() {
             return Err(
                 "No game configured. Fill in the game profile, or set a launch command, \
-                 in the Config tab."
+                 in Settings."
                     .into(),
             );
         }
@@ -389,10 +389,10 @@ impl LauncherConfig {
 
     pub fn validate_account(&self) -> Result<(), String> {
         if self.fut_persona_id == 0 {
-            return Err("No EA persona ID configured. Set the account in the Config tab.".into());
+            return Err("No account yet. Create one from the Get started tab.".into());
         }
         if self.fut_persona_name.trim().is_empty() {
-            return Err("No EA persona name configured. Set the account in the Config tab.".into());
+            return Err("Account has no persona name. Recreate it from Get started.".into());
         }
         if self.fut_account_level == 0 {
             return Err("EA account level must be at least 1.".into());
@@ -408,6 +408,21 @@ impl LauncherConfig {
         Ok(())
     }
 
+    /// Whether an account has been claimed from the server (see
+    /// [`crate::account_sync::discover`]). Distinct from
+    /// [`Self::validate_account`], which also polices the derived EASFC values:
+    /// this answers only "does this install know who is playing?".
+    pub fn account_configured(&self) -> bool {
+        self.fut_persona_id != 0 && !self.fut_persona_name.trim().is_empty()
+    }
+
+    /// Whether the launcher should open on the guided first-run flow instead of
+    /// the dashboard. Keyed on the two things a new user cannot be expected to
+    /// guess: where the server is, and who they are.
+    pub fn needs_onboarding(&self) -> bool {
+        self.validate_server().is_err() || !self.account_configured()
+    }
+
     /// The exact `openfut.cfg` bytes to write for the hook, or an error if the
     /// server isn't validly configured (never emits a loopback fallback).
     ///
@@ -696,12 +711,38 @@ mod tests {
     #[test]
     fn launch_requires_a_valid_ea_account() {
         let mut c = LauncherConfig::default();
-        assert!(c.validate_account().unwrap_err().contains("persona ID"));
+        // A fresh install has no account, and must say so rather than launching
+        // FIFA as persona 0.
+        assert!(!c.account_configured());
+        assert!(c.validate_account().is_err());
         c.fut_persona_id = 12345678;
+        assert!(
+            !c.account_configured(),
+            "an id without a name is not an account"
+        );
         assert!(c.validate_account().unwrap_err().contains("persona name"));
         c.fut_persona_name = "TEST_USER".into();
+        assert!(c.account_configured());
         assert!(c.validate_account().is_ok());
         c.fut_account_experience = 1001;
         assert!(c.validate_account().unwrap_err().contains("XP"));
     }
+
+    #[test]
+    fn onboarding_is_needed_until_both_server_and_account_are_known() {
+        // Drives which tab the launcher opens on, so the two halves must both
+        // count: a server with no account is still a dead end for a new user.
+        let mut c = LauncherConfig::default();
+        assert!(c.needs_onboarding());
+        c.openfut_server_host = "10.10.0.120".into();
+        assert!(
+            c.needs_onboarding(),
+            "a server alone cannot launch anything"
+        );
+        c.fut_persona_id = 33_068_179;
+        c.fut_persona_name = "CAGE".into();
+        assert!(!c.needs_onboarding());
+        c.openfut_server_host.clear();
+        assert!(c.needs_onboarding(), "losing the server reopens the flow");
+    }
 }