feat: event store, pattern inference, and routine proposals

- Add events table (migration #4): stores normalized (action, object, ts)
  triples extracted from facts, indexed for recurrence detection.
- Add proposed_routines table: stores inferred recurring patterns with
  proposed/accepted/dismissed status and optional linked reminder.
- Add pattern package: Extractor normalizes fact text into (action, object)
  pairs with TTS normalization; Detector groups events to find recurring
  patterns and proposes routines.
- Add internal/ttsnorm: text normalization pipeline for Russian/English
  (lowercase, punctuation strip, number normalization, stopword removal).
- Add chat seed file for LLM phraser.

internal/pattern/extractor_test.go

@@ -0,0 +1,56 @@
+package pattern
+
+import (
+	"testing"
+	"time"
+)
+
+func TestExtractSimpleAction(t *testing.T) {
+	now := time.Now().UTC()
+
+	tests := []struct {
+		name       string
+		key        string
+		value      string
+		wantAction string
+		wantObject string
+		wantNil    bool
+	}{
+		{"refill english", "water_fountain", "refilled", "refill", "water_fountain", false},
+		{"refill russian", "cat_water", "налил", "refill", "cat_water", false},
+		{"fed cat", "cat_food", "fed", "feed", "cat_food", false},
+		{"clean litter", "litter_box", "почистил", "clean", "litter_box", false},
+		{"walked dog", "dog_walk", "walked", "walk", "dog_walk", false},
+		{"took medicine", "medicine", "took", "take", "medicine", false},
+		{"watered plants", "plants", "watered", "water", "plants", false},
+		{"json value skipped", "weight", `{"kg": 82}`, "", "", true},
+		{"empty value skipped", "something", "", "", "", true},
+		{"unrecognized action", "door", "opened", "", "", true},
+		{"case insensitive", "WATER_FOUNTAIN", "REFILLED", "refill", "water_fountain", false},
+		{"whitespace trimmed", "  cat_bed  ", "  cleaned  ", "clean", "cat_bed", false},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			ev := Extract(42, tc.key, tc.value, now)
+			if tc.wantNil {
+				if ev != nil {
+					t.Fatalf("want nil, got %+v", ev)
+				}
+				return
+			}
+			if ev == nil {
+				t.Fatal("want event, got nil")
+			}
+			if ev.Action != tc.wantAction {
+				t.Fatalf("action: want %q, got %q", tc.wantAction, ev.Action)
+			}
+			if ev.Object != tc.wantObject {
+				t.Fatalf("object: want %q, got %q", tc.wantObject, ev.Object)
+			}
+			if ev.FactID != 42 {
+				t.Fatalf("fact_id: want 42, got %d", ev.FactID)
+			}
+		})
+	}
+}