feat(desktop): global agent config defaults with readiness/spawn parity

desktop/scripts/check-file-sizes.mjs

@@ -60,7 +60,11 @@ const overrides = new Map([
   // config-bridge: get_agent_config_surface/write_agent_config_field/put_agent_session_config
   // commands add ~40 lines. Queued to split.
   // branch cut; override bumped to cover the merged total. Queued to split.
-  ["src-tauri/src/commands/agents.rs", 1437],
+  // global-agent-config: build_deploy_payload threads global config fallback
+  // for provider/model/env_vars (+4 lines). cargo fmt reflowed 2 more lines.
+  // deploy-resolver: resolve_deploy_model_provider fn + doc comment (+6 lines).
+  // Queued to split.
+  ["src-tauri/src/commands/agents.rs", 1449],
   // #1418 read-path fix: get_thread_replies' blocker fix (shared TIMELINE_KINDS
   // const + build_thread_replies_filter helper, mirroring the channel sibling so
   // the two p-gate filters can't drift) plus two guard unit tests. The file was
@@ -84,7 +88,9 @@ const overrides = new Map([
   // activity-feed threads avatar_url into build_managed_agent_summary for the
   // assistant-bubble pinned snapshot.
   // +1 for agent_pubkey field in setup payload (config-nudge card wire).
-  ["src-tauri/src/managed_agents/runtime.rs", 2208],
+  // global-agent-config: spawn_agent_child loads global config and merges as
+  // lowest env layer (+8 lines). Queued to split.
+  ["src-tauri/src/managed_agents/runtime.rs", 2216],
   // config-bridge setup-payload env-boundary fix adds readiness wiring in
   // spawn_agent_child; load-bearing security fix, queued to split.
   ["src-tauri/src/managed_agents/config_bridge/reader.rs", 1016],
@@ -94,7 +100,8 @@ const overrides = new Map([
   // New file in this PR; queued to split.
   // +2 readiness integration tests for flat-DATABRICKS_HOST canonicalization fix.
   // +1 cargo fmt whitespace reformat (readiness.rs closures inline after rebase).
-  ["src-tauri/src/managed_agents/readiness.rs", 1150],
+  // +16: resolve_effective_agent_env + global-config readiness wiring (#1448 base).
+  ["src-tauri/src/managed_agents/readiness.rs", 1166],
   // applyWorkspace reposDir parameter plus the validateReposDir binding,
   // threaded through Tauri invokes for configurable repos_dir, plus the
   // harness-persona-sync `harnessOverride` create-input bit — load-bearing
@@ -114,7 +121,9 @@ const overrides = new Map([
   // CreateAgentDialog). +23 lines of gate wiring. Queued to split.
   // config-bridge-aware requirements: useRuntimeFileConfigQuery wiring adds
   // ~16 lines. Queued to split.
-  ["src/features/agents/ui/PersonaDialog.tsx", 1032],
+  // +2 lines: filter managed provider key from requiredEnvKeys at the
+  // PersonaAdvancedFields call site to suppress the dead-input locked row.
+  ["src/features/agents/ui/PersonaDialog.tsx", 1034],
   // harness-persona-sync feature growth, queued to split in the resolver-unify
   // refactor followup. discovery.rs is dominated by the new test module
   // (the effective_agent_command / divergent / create-time override matrix);
@@ -146,7 +155,8 @@ const overrides = new Map([
   // props restored after 826d735fe removal (UserProfilePanel.tsx still needs them).
   ["src/features/profile/ui/UserProfilePanelSections.tsx", 1140],
   // +14 for openEditAgent event subscription (config-nudge card "Open Edit Agent" action).
-  ["src/features/profile/ui/UserProfilePanel.tsx", 1014],
+  // +11 for editAgentFocus state + initialFocus prop threading (deep-link granularity).
+  ["src/features/profile/ui/UserProfilePanel.tsx", 1025],
   // PersistBackend enum + marker-on-keyring-success plumbing and its three
   // fail-closed regression tests (silent identity rotation on keyring outage).
   // A small overage from load-bearing security plumbing on a file already at

desktop/src-tauri/src/commands/agent_config.rs

@@ -14,7 +14,8 @@ use crate::{
         },
         current_instance_id, effective_agent_command, known_acp_runtime, load_managed_agents,
         load_personas, resolve_effective_prompt_model_provider, save_managed_agents,
-        sync_managed_agent_processes, KnownAcpRuntime, ManagedAgentRecord, PersonaRecord,
+        sync_managed_agent_processes, GlobalAgentConfig, KnownAcpRuntime, ManagedAgentRecord,
+        PersonaRecord,
     },
 };
 
@@ -36,13 +37,17 @@ pub struct RuntimeFileConfigSubset {
     pub satisfied_env_keys: Vec<String>,
 }
 
-/// Resolve the config surface with persona values applied.
+/// Resolve the config surface with persona and global default values applied.
 ///
 /// The pipeline: resolve the linked persona's prompt/model/provider, inject
 /// each into the record only where the record lacks its own value, let
 /// `read_config_surface` tag those injected fields `BuzzExplicit`, then re-tag
 /// exactly the injected fields to `PersonaDefault`.
 ///
+/// Global defaults fill in when neither the record nor the linked persona
+/// provides a value. They are re-tagged to `GlobalDefault` so the UI can
+/// display "inherited from global defaults".
+///
 /// The re-tag is triple-gated — a field is re-tagged only when (a) the record
 /// did not already have it (`!had_*`), (b) the surface produced the field, and
 /// (c) the reader tagged it `BuzzExplicit`. A value the user set explicitly in
@@ -52,6 +57,7 @@ fn resolve_config_surface(
     personas: &[PersonaRecord],
     runtime_meta: Option<&KnownAcpRuntime>,
     session_cache: Option<&SessionConfigCache>,
+    global: &GlobalAgentConfig,
 ) -> RuntimeConfigSurface {
     let had_prompt =
         record.system_prompt.is_some() || record.env_vars.contains_key("BUZZ_ACP_SYSTEM_PROMPT");
@@ -87,9 +93,21 @@ fn resolve_config_surface(
             None
         }
     } else {
+        // Prefer persona as baseline, fall back to global when persona has none
+        // and the model was overridden mid-session (global-default agent).
         persona_model
             .clone()
             .map(|m| (m, ConfigOrigin::PersonaDefault))
+            .or_else(|| {
+                if model_overridden {
+                    global
+                        .model
+                        .clone()
+                        .map(|m| (m, ConfigOrigin::GlobalDefault))
+                } else {
+                    None
+                }
+            })
     };
 
     // Inject resolved persona values into the record where absent.
@@ -109,6 +127,24 @@ fn resolve_config_surface(
         }
     }
 
+    // Inject global defaults where neither the record nor the persona had a value.
+    // Track injection so we can re-tag to GlobalDefault after the reader.
+    let inject_global_model = !had_model && record.model.is_none();
+    let inject_global_provider = !had_provider
+        && !provider_env_key.is_empty()
+        && !record.env_vars.contains_key(provider_env_key);
+
+    if inject_global_model {
+        record.model = global.model.clone();
+    }
+    if inject_global_provider {
+        if let Some(ref gprov) = global.provider {
+            record
+                .env_vars
+                .insert(provider_env_key.to_string(), gprov.clone());
+        }
+    }
+
     let mut surface = read_config_surface(
         &record,
         runtime_meta,
@@ -120,13 +156,21 @@ fn resolve_config_surface(
     if !had_prompt {
         retag_persona_default(&mut surface.normalized.system_prompt);
     }
-    if !had_model {
+    if !had_model && !inject_global_model {
         retag_persona_default(&mut surface.normalized.model);
     }
-    if !had_provider && !provider_env_key.is_empty() {
+    if !had_provider && !provider_env_key.is_empty() && !inject_global_provider {
         retag_persona_default(&mut surface.normalized.provider);
     }
 
+    // Re-tag global-sourced fields from BuzzExplicit to GlobalDefault.
+    if inject_global_model {
+        retag_global_default(&mut surface.normalized.model);
+    }
+    if inject_global_provider {
+        retag_global_default(&mut surface.normalized.provider);
+    }
+
     // Re-tag persona-snapshotted model from BuzzExplicit to PersonaDefault.
     // Persona-created agents have record.model set at create time from the
     // persona snapshot — had_model is true, but the model came from the persona,
@@ -184,6 +228,15 @@ pub fn get_runtime_file_config(runtime_id: String) -> Option<RuntimeFileConfigSu
     }
 }
 
+/// Re-tag a field's origin from `BuzzExplicit` to `GlobalDefault`, leaving any
+/// other origin untouched. No-op when the field is absent.
+fn retag_global_default(field: &mut Option<NormalizedField>) {
+    if let Some(field) = field {
+        if field.origin == ConfigOrigin::BuzzExplicit {
+            field.origin = ConfigOrigin::GlobalDefault;
+        }
+    }
+}
 /// Get the full config surface for a managed agent.
 ///
 /// Returns normalized + advanced config from all available tiers.
@@ -227,12 +280,14 @@ pub async fn get_agent_config_surface(
     );
     let runtime_meta = known_acp_runtime(&effective_cmd);
     let session_cache = state.get_session_cache(&pubkey);
+    let global = crate::managed_agents::load_global_agent_config(&app).unwrap_or_default();
 
     Ok(resolve_config_surface(
         record,
         &personas,
         runtime_meta,
         session_cache.as_ref(),
+        &global,
     ))
 }
 
@@ -544,7 +599,13 @@ mod tests {
         record.model = Some("explicit-model".to_string());
         let personas = vec![persona_with_model("persona-model")];
 
-        let surface = resolve_config_surface(record, &personas, Some(goose_runtime()), None);
+        let surface = resolve_config_surface(
+            record,
+            &personas,
+            Some(goose_runtime()),
+            None,
+            &Default::default(),
+        );
 
         let model = surface.normalized.model.as_ref().expect("model resolved");
         assert_eq!(model.value.as_deref(), Some("explicit-model"));
@@ -565,8 +626,13 @@ mod tests {
         let personas: Vec<PersonaRecord> = vec![];
         let cache = session_cache("model-y", false);
 
-        let surface =
-            resolve_config_surface(record, &personas, Some(goose_runtime()), Some(&cache));
+        let surface = resolve_config_surface(
+            record,
+            &personas,
+            Some(goose_runtime()),
+            Some(&cache),
+            &Default::default(),
+        );
         let model = surface.normalized.model.expect("model resolved");
 
         assert_eq!(model.value.as_deref(), Some("model-x"));
@@ -588,8 +654,13 @@ mod tests {
         let personas: Vec<PersonaRecord> = vec![];
         let cache = session_cache("model-y", true);
 
-        let surface =
-            resolve_config_surface(record, &personas, Some(goose_runtime()), Some(&cache));
+        let surface = resolve_config_surface(
+            record,
+            &personas,
+            Some(goose_runtime()),
+            Some(&cache),
+            &Default::default(),
+        );
         let model = surface.normalized.model.expect("model resolved");
 
         assert_eq!(model.value.as_deref(), Some("model-y"));
@@ -610,8 +681,13 @@ mod tests {
         let personas: Vec<PersonaRecord> = vec![];
         let cache = session_cache("model-x", true);
 
-        let surface =
-            resolve_config_surface(record, &personas, Some(goose_runtime()), Some(&cache));
+        let surface = resolve_config_surface(
+            record,
+            &personas,
+            Some(goose_runtime()),
+            Some(&cache),
+            &Default::default(),
+        );
         let model = surface.normalized.model.expect("model resolved");
 
         assert_eq!(model.value.as_deref(), Some("model-x"));
@@ -629,13 +705,63 @@ mod tests {
         let personas = vec![persona_with_model("persona-model")];
         let cache = session_cache("model-y", true);
 
-        let surface =
-            resolve_config_surface(record, &personas, Some(goose_runtime()), Some(&cache));
+        let surface = resolve_config_surface(
+            record,
+            &personas,
+            Some(goose_runtime()),
+            Some(&cache),
+            &Default::default(),
+        );
         let model = surface.normalized.model.expect("model resolved");
 
         assert_eq!(model.value.as_deref(), Some("model-y"));
         assert_eq!(model.origin, ConfigOrigin::RuntimeOverride);
         assert_eq!(model.overridden_value.as_deref(), Some("persona-model"));
         assert_eq!(model.overridden_origin, Some(ConfigOrigin::PersonaDefault));
     }
+
+    /// Fix 2 regression: a global-default-only agent (no record model, no
+    /// persona model, but global has a model) that live-switches mid-session
+    /// must render the global model as the secondary tagged `GlobalDefault`.
+    /// Before the fix, `baseline` was `None` in the `!had_model` arm when
+    /// persona has no model, so `read_config_surface` had no secondary to
+    /// surface. Fails against pre-fix code where the baseline arm returned
+    /// `None` when `!had_model && persona_model.is_none() && model_overridden`.
+    #[test]
+    fn global_default_live_switch_renders_global_model_as_secondary_global_default() {
+        // Record has no model, no persona, global provides the model.
+        let mut record = agent_record();
+        record.persona_id = None;
+        // record.model = None (set by agent_record())
+        let personas: Vec<PersonaRecord> = vec![];
+        let cache = session_cache("model-y", true);
+        let global = crate::managed_agents::GlobalAgentConfig {
+            model: Some("global-model".to_string()),
+            ..Default::default()
+        };
+
+        let surface = resolve_config_surface(
+            record,
+            &personas,
+            Some(goose_runtime()),
+            Some(&cache),
+            &global,
+        );
+        let model = surface.normalized.model.expect("model resolved");
+
+        // Live model wins as primary.
+        assert_eq!(model.value.as_deref(), Some("model-y"));
+        assert_eq!(model.origin, ConfigOrigin::RuntimeOverride);
+        // Global model surfaces as secondary, tagged GlobalDefault.
+        assert_eq!(
+            model.overridden_value.as_deref(),
+            Some("global-model"),
+            "global model must be the override baseline secondary"
+        );
+        assert_eq!(
+            model.overridden_origin,
+            Some(ConfigOrigin::GlobalDefault),
+            "override baseline origin must be GlobalDefault, not PersonaDefault or BuzzExplicit"
+        );
+    }
 }