LLM call logging, plan persistence API, quote-to-feedback UX, requirement input improvements

- Add llm_call_log table and per-call timing/token tracking in agent loop
- New GET /workflows/{id}/plan endpoint to restore plan from snapshots on page load
- New GET /workflows/{id}/llm-calls endpoint + WS LlmCallLog broadcast
- Parse Usage from LLM API response (prompt_tokens, completion_tokens)
- Detailed mode toggle in execution log showing LLM call cards with phase/tokens/latency
- Quote-to-feedback: hover quote buttons on plan steps and log entries, multi-quote chips in comment input
- Requirement input: larger textarea, multi-line display with pre-wrap and scroll

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/db.rs

@@ -158,6 +158,32 @@ impl Database {
         .execute(&self.pool)
         .await?;
 
+        sqlx::query(
+            "CREATE TABLE IF NOT EXISTS llm_call_log (
+                id TEXT PRIMARY KEY,
+                workflow_id TEXT NOT NULL REFERENCES workflows(id),
+                step_order INTEGER NOT NULL,
+                phase TEXT NOT NULL,
+                messages_count INTEGER NOT NULL,
+                tools_count INTEGER NOT NULL,
+                tool_calls TEXT NOT NULL DEFAULT '[]',
+                text_response TEXT NOT NULL DEFAULT '',
+                prompt_tokens INTEGER,
+                completion_tokens INTEGER,
+                latency_ms INTEGER NOT NULL,
+                created_at TEXT NOT NULL DEFAULT (datetime('now'))
+            )"
+        )
+        .execute(&self.pool)
+        .await?;
+
+        // Migration: add text_response column to llm_call_log
+        let _ = sqlx::query(
+            "ALTER TABLE llm_call_log ADD COLUMN text_response TEXT NOT NULL DEFAULT ''"
+        )
+        .execute(&self.pool)
+        .await;
+
         sqlx::query(
             "CREATE TABLE IF NOT EXISTS timers (
                 id TEXT PRIMARY KEY,
@@ -237,3 +263,19 @@ pub struct Timer {
     pub last_run_at: String,
     pub created_at: String,
 }
+
+#[derive(Debug, Clone, Serialize, Deserialize, sqlx::FromRow)]
+pub struct LlmCallLogEntry {
+    pub id: String,
+    pub workflow_id: String,
+    pub step_order: i32,
+    pub phase: String,
+    pub messages_count: i32,
+    pub tools_count: i32,
+    pub tool_calls: String,
+    pub text_response: String,
+    pub prompt_tokens: Option<i32>,
+    pub completion_tokens: Option<i32>,
+    pub latency_ms: i32,
+    pub created_at: String,
+}