P1 backend: chat persistence, tc-llm providers, runtime loop, gateway SSE

- tc-db: sessions/messages/steps/runs/run_events repos (atomic seq assignment,
  history with ordered step traces, journal replay-from-offset); migration 0003
- tc-llm: provider-neutral ChatRequest/LlmEvent; ScriptedProvider (scenario
  TOML, word-level deltas, multi-turn tool legs — ships in production for
  e2e/air-gap smoke), AnthropicProvider (Messages SSE), OpenAiCompatProvider
  (vLLM/Ollama/llama.cpp); opt-in live tests via TC_LIVE_LLM=1
- tc-runtime: run loop with persist-before-emit event journal, real built-in
  clock.now tool, step rows on the reply message, tool-error resilience,
  broadcast channels for live attach
- tc-api: agent CRUD + settings/full (tenant-isolated, RBAC'd, audited),
  sessions create/list/history?tools=true, POST /api/gateway SSE with
  monotonic ids and exact resumeFrom journal replay (tested equal to live)
- teamclaw-server: config-driven provider factory

83 Rust tests green, all against real Postgres / real TCP.

Co-Authored-By: Claude Fable 5 <[email protected]>

crates/tc-runtime/src/events.rs

@@ -0,0 +1,53 @@
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+use uuid::Uuid;
+
+/// One gateway event with its journal sequence number. The wire contract
+/// with the frontend (`frontend/src/lib/gateway/events.ts` mirrors it).
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct RunEventEnvelope {
+    pub seq: i64,
+    #[serde(flatten)]
+    pub event: RunEventBody,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum RunEventBody {
+    RunStarted {
+        run_id: Uuid,
+    },
+    TextDelta {
+        delta: String,
+    },
+    StepStarted {
+        step_seq: i32,
+        tool: String,
+        input: Value,
+    },
+    StepFinished {
+        step_seq: i32,
+        status: String,
+        output: Value,
+    },
+    RunCompleted {
+        message_id: String,
+    },
+    Error {
+        message: String,
+    },
+}
+
+impl RunEventBody {
+    /// Stable name stored in `run_events.event_type`.
+    pub fn type_name(&self) -> &'static str {
+        match self {
+            RunEventBody::RunStarted { .. } => "run_started",
+            RunEventBody::TextDelta { .. } => "text_delta",
+            RunEventBody::StepStarted { .. } => "step_started",
+            RunEventBody::StepFinished { .. } => "step_finished",
+            RunEventBody::RunCompleted { .. } => "run_completed",
+            RunEventBody::Error { .. } => "error",
+        }
+    }
+}