feat: persist LLM/TTS backend choice + reset/repeat context + quick-search + diagnostics

Closes the UX hole I created in 5c72450: voice-swap to Ollama used to vanish
after restart. Plus P0.3 (long-standing roadmap item) and two new packs.

Persistent backend choice (crates/jarvis-core/src/db/structs.rs)
  - Settings struct gains llm_backend + tts_backend fields (both String,
    "" / "auto" = follow env/auto-detect).
  - set("llm_backend", "groq"|"ollama"|"auto") validates input.
  - llm::init_global() reads DB first, then JARVIS_LLM env, then auto-detect.
  - llm::swap_to() now persists the choice via db::save_settings.
  - Voice swap "переключись на локальный" now survives restart.

Shared conversation history (P0.3, crates/jarvis-core/src/llm/mod.rs)
  - HISTORY: Lazy<RwLock<Option<ConversationHistory>>> singleton.
  - Helpers: init_history, history_push_user, history_push_assistant,
    history_snapshot, history_clear, history_pop_last_user, history_last_assistant.
  - llm_fallback migrated off its own Mutex<History> — now reads/writes shared.
  - ConversationHistory gains last_assistant() method.

New Lua APIs
  - jarvis.llm_reset()        → clear conversation turns (keeps system prompt).
  - jarvis.llm_last_reply()   → string or nil (last assistant message text).
  - jarvis.health()           → debug table {tts_backend, llm_backend, llm_model,
                                  active_profile, memory_facts, scheduled_tasks,
                                  language, voice, microphone, vosk_model,
                                  noise_suppression}. No secrets included.

New voice packs
  - resources/commands/llm_context/   (P0.3)
    * "сбрось контекст" / "забудь разговор"     → llm.reset
    * "повтори последнее" / "повтори ответ"     → llm.repeat (uses last_assistant)
  - resources/commands/quick_search/   (imba P1 item)
    * "найди в гугле <X>" / "загугли <X>"
    * Uses DuckDuckGo Instant Answer API (api.duckduckgo.com, no key required).
      Pulls AbstractText or RelatedTopics into LLM prompt; falls back to pure
      LLM knowledge if DDG returns nothing useful. Speaks 2-4 sentence answer.
  - resources/commands/diagnostics/
    * "диагностика" / "доложи о себе" / "статус"
    * Reads jarvis.health() and speaks a one-line summary. Useful when
      debugging — user can read out their current state for a bug report.

Build: cargo build --release -p jarvis-app -p jarvis-gui green.
Tests: 52/52 jarvis-core unit tests pass.

crates/jarvis-core/src/db/structs.rs

@@ -33,6 +33,19 @@ pub struct Settings {
     pub language: String,
 
     pub api_keys: ApiKeys,
+
+    /// Preferred LLM backend ("groq" | "ollama" | empty=auto). Empty/auto means
+    /// the JARVIS_LLM env var or auto-detect (Groq if GROQ_TOKEN set else Ollama)
+    /// decides. When the user runs `jarvis.llm_switch(...)` the result is
+    /// persisted here so it survives restart.
+    #[serde(default)]
+    pub llm_backend: String,
+
+    /// Preferred TTS backend ("sapi" | "piper" | "silero" | empty=auto). Same
+    /// rules as `llm_backend`. Empty falls back to JARVIS_TTS env var, then
+    /// auto-detect.
+    #[serde(default)]
+    pub tts_backend: String,
 }
 
 fn default_intent_backend() -> String { config::DEFAULT_INTENT_BACKEND.to_string() }
@@ -60,6 +73,8 @@ impl Settings {
             "language"                  => Some(self.language.clone()),
             "api_key__picovoice"        => Some(self.api_keys.picovoice.clone()),
             "api_key__openai"           => Some(self.api_keys.openai.clone()),
+            "llm_backend"               => Some(self.llm_backend.clone()),
+            "tts_backend"               => Some(self.tts_backend.clone()),
             _ => None,
         }
     }
@@ -120,6 +135,22 @@ impl Settings {
             "api_key__openai" => {
                 self.api_keys.openai = val.to_string();
             }
+            "llm_backend" => {
+                // empty / "auto" / "groq" / "ollama" — anything else rejected
+                match val.trim().to_lowercase().as_str() {
+                    "" | "auto" => self.llm_backend = String::new(),
+                    "groq" => self.llm_backend = "groq".into(),
+                    "ollama" => self.llm_backend = "ollama".into(),
+                    other => return Err(format!("unknown llm_backend: '{}'", other)),
+                }
+            }
+            "tts_backend" => {
+                match val.trim().to_lowercase().as_str() {
+                    "" | "auto" => self.tts_backend = String::new(),
+                    "sapi" | "piper" | "silero" => self.tts_backend = val.to_lowercase(),
+                    other => return Err(format!("unknown tts_backend: '{}'", other)),
+                }
+            }
             _ => return Err(format!("unknown setting: '{}'", key)),
         }
         Ok(())
@@ -142,6 +173,8 @@ impl Settings {
             "language",
             "api_key__picovoice",
             "api_key__openai",
+            "llm_backend",
+            "tts_backend",
         ]
     }
 }
@@ -173,6 +206,9 @@ impl Default for Settings {
                 picovoice: String::from(""),
                 openai: String::from(""),
             },
+
+            llm_backend: String::new(),
+            tts_backend: String::new(),
         }
     }
 }

crates/jarvis-core/src/llm/history.rs

@@ -58,6 +58,11 @@ impl ConversationHistory {
         }
     }
 
+    /// Return the most recent assistant message, or None if none yet.
+    pub fn last_assistant(&self) -> Option<&ChatMessage> {
+        self.turns.iter().rev().find(|m| m.role == "assistant")
+    }
+
     fn truncate(&mut self) {
         if self.turns.len() > self.max_turns {
             let drop = self.turns.len() - self.max_turns;

crates/jarvis-core/src/llm/mod.rs

@@ -12,6 +12,52 @@ use once_cell::sync::Lazy;
 use parking_lot::RwLock;
 use std::sync::Arc;
 
+// ─── Shared conversation history ───────────────────────────────────────────
+//
+// Single global history so the LLM fallback chat, the Lua reset/repeat helpers,
+// and any future IPC handler all operate on the same buffer. Initialised on
+// boot via `init_history(system_prompt, max_turns)`.
+
+static HISTORY: Lazy<RwLock<Option<ConversationHistory>>> = Lazy::new(|| RwLock::new(None));
+
+pub fn init_history(system_prompt: impl Into<String>, max_turns: usize) {
+    *HISTORY.write() = Some(ConversationHistory::new(system_prompt, max_turns));
+}
+
+pub fn history_push_user(content: impl Into<String>) {
+    if let Some(h) = HISTORY.write().as_mut() {
+        h.push_user(content);
+    }
+}
+
+pub fn history_push_assistant(content: impl Into<String>) {
+    if let Some(h) = HISTORY.write().as_mut() {
+        h.push_assistant(content);
+    }
+}
+
+pub fn history_snapshot() -> Vec<ChatMessage> {
+    HISTORY.read().as_ref().map(|h| h.snapshot()).unwrap_or_default()
+}
+
+pub fn history_clear() {
+    if let Some(h) = HISTORY.write().as_mut() {
+        h.clear();
+    }
+}
+
+pub fn history_pop_last_user() {
+    if let Some(h) = HISTORY.write().as_mut() {
+        h.pop_last_user();
+    }
+}
+
+/// Return the most recent assistant message text, or None.
+pub fn history_last_assistant() -> Option<String> {
+    HISTORY.read().as_ref()
+        .and_then(|h| h.last_assistant().map(|m| m.content.clone()))
+}
+
 /// Shared mutable LLM client. Modules read via `current()`; the user can
 /// hot-swap backends at runtime via `swap_to(LlmBackend::Ollama)` etc.
 ///
@@ -19,12 +65,28 @@ use std::sync::Arc;
 /// `init_global()` was never called).
 static GLOBAL: Lazy<RwLock<Option<Arc<LlmClient>>>> = Lazy::new(|| RwLock::new(None));
 
-/// Initialise the global client from env vars (`JARVIS_LLM`, `GROQ_TOKEN`, ...).
+/// Initialise the global client. Precedence:
+///   1. Settings DB `llm_backend` field (if non-empty)
+///   2. `JARVIS_LLM` env var
+///   3. Auto-detect (Groq if `GROQ_TOKEN`, else Ollama)
+///
 /// Idempotent — replaces any previous global. Returns Ok even when the chosen
 /// backend can't be probed: an Ollama server may not be running yet but we
 /// stash the client anyway and let calls fail on first request.
 pub fn init_global() -> Result<(), ConfigError> {
-    let c = LlmClient::from_env()?;
+    // Try DB-persisted choice first.
+    let persisted = crate::DB.get().and_then(|db| {
+        let s = db.read();
+        let backend = s.llm_backend.trim().to_string();
+        if backend.is_empty() { None } else { parse_backend(&backend) }
+    });
+
+    let c = match persisted {
+        Some(LlmBackend::Groq) => LlmClient::groq()?,
+        Some(LlmBackend::Ollama) => LlmClient::ollama(),
+        None => LlmClient::from_env()?,
+    };
+
     log::info!("LLM global initialised: backend={}, model={}", c.backend().name(), c.model());
     *GLOBAL.write() = Some(Arc::new(c));
     Ok(())
@@ -45,6 +107,7 @@ pub fn current_backend_name() -> &'static str {
 }
 
 /// Hot-swap to a different backend. Returns the new backend's name on success.
+/// Persists the choice to the settings DB so it survives restart.
 pub fn swap_to(backend: LlmBackend) -> Result<&'static str, ConfigError> {
     let c = match backend {
         LlmBackend::Groq => LlmClient::groq()?,
@@ -53,6 +116,21 @@ pub fn swap_to(backend: LlmBackend) -> Result<&'static str, ConfigError> {
     let name = c.backend().name();
     log::info!("LLM swapped → backend={}, model={}", name, c.model());
     *GLOBAL.write() = Some(Arc::new(c));
+
+    // Persist to settings DB (best-effort — log on failure, don't propagate).
+    if let Some(db) = crate::DB.get() {
+        let snapshot = {
+            let mut s = db.write();
+            s.llm_backend = name.to_string();
+            s.clone()
+        };
+        if let Err(e) = crate::db::save_settings(&snapshot) {
+            log::warn!("LLM swap: failed to persist to settings DB: {}", e);
+        } else {
+            log::info!("LLM choice persisted: {}", name);
+        }
+    }
+
     Ok(name)
 }
 

crates/jarvis-core/src/lua/api.rs

@@ -12,4 +12,5 @@ pub mod memory;
 pub mod profile;
 pub mod vision;
 pub mod scheduler;
-pub mod cmd;
+pub mod cmd;
+pub mod health;

crates/jarvis-core/src/lua/api/health.rs

@@ -0,0 +1,50 @@
+//! `jarvis.health()` — debug snapshot of active runtime state.
+//!
+//! Returns a table that can be JSON-encoded for bug reports. Doesn't include
+//! secrets (no API keys, no LLM history content).
+//!
+//! Example use from Lua:
+//!   local h = jarvis.health()
+//!   for k, v in pairs(h) do print(k, v) end
+
+use mlua::{Lua, Table};
+
+pub fn register(lua: &Lua, jarvis: &Table) -> mlua::Result<()> {
+    let health_fn = lua.create_function(|lua, ()| {
+        let t = lua.create_table()?;
+
+        // TTS
+        t.set("tts_backend", crate::tts::backend().name())?;
+
+        // LLM
+        t.set("llm_backend", crate::llm::current_backend_name())?;
+        if let Some(c) = crate::llm::current() {
+            t.set("llm_model", c.model().to_string())?;
+        }
+
+        // Profile
+        t.set("active_profile", crate::profiles::active_name())?;
+
+        // Memory size
+        t.set("memory_facts", crate::long_term_memory::all().len())?;
+
+        // Scheduler size
+        t.set("scheduled_tasks", crate::scheduler::list().len())?;
+
+        // Language
+        t.set("language", crate::i18n::get_language())?;
+
+        // Voice from settings
+        if let Some(db) = crate::DB.get() {
+            let s = db.read();
+            t.set("voice", s.voice.clone())?;
+            t.set("microphone", s.microphone)?;
+            t.set("vosk_model", s.vosk_model.clone())?;
+            t.set("noise_suppression", format!("{:?}", s.noise_suppression))?;
+        }
+
+        Ok(t)
+    })?;
+    jarvis.set("health", health_fn)?;
+    Ok(())
+}

crates/jarvis-core/src/lua/api/llm.rs

@@ -98,5 +98,25 @@ pub fn register(lua: &Lua, jarvis: &Table) -> mlua::Result<()> {
     })?;
     jarvis.set("llm_switch", switch_fn)?;
 
+    // Clear conversation turns (keeps system prompt). Returns true if history was
+    // initialised, false if LLM is not configured.
+    let reset_fn = lua.create_function(|_, ()| {
+        llm::history_clear();
+        Ok(true)
+    })?;
+    jarvis.set("llm_reset", reset_fn)?;
+
+    // Return the most recent assistant message text, or nil.
+    let last_fn = lua.create_function(|lua, ()| {
+        match llm::history_last_assistant() {
+            Some(text) => {
+                let s = lua.create_string(text)?;
+                Ok(Value::String(s))
+            }
+            None => Ok(Value::Nil),
+        }
+    })?;
+    jarvis.set("llm_last_reply", last_fn)?;
+
     Ok(())
 }

crates/jarvis-core/src/lua/engine.rs

@@ -82,6 +82,7 @@ impl LuaEngine {
         api::profile::register(&self.lua, &jarvis)?;
         api::scheduler::register(&self.lua, &jarvis)?;
         api::cmd::register(&self.lua, &jarvis)?;
+        api::health::register(&self.lua, &jarvis)?;
 
         // sandbox-controlled APIs
         if self.sandbox.allows_http() {