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.go

@@ -0,0 +1,85 @@
+// Package pattern extracts normalized events from facts and detects recurring
+// patterns to propose as routines (recurring reminders).
+//
+// The pipeline: fact write → extractor (action+object) → detector (intervals) →
+// proposed routine → human confirms → recurring reminder.
+package pattern
+
+import (
+	"strings"
+	"time"
+)
+
+// Event is a normalized, derived observation — the output of the extractor
+// and the input to the pattern detector.
+type Event struct {
+	FactID int64
+	Action string // normalized action, e.g. "refill"
+	Object string // normalized object, e.g. "cat_water_fountain"
+	Ts     time.Time
+}
+
+// actionLexicon maps observed value words to canonical actions. The key is the
+// canonical form; the values are observed inflections/alternatives (lowercase).
+// Pure additive — unrecognized values silently produce no event (false
+// negative), which is harmless.
+var actionLexicon = map[string][]string{
+	"refill": {"refilled", "refill", "fills", "filling", "заправил", "налил", "долил", "пополнил"},
+	"feed":   {"fed", "feed", "feeds", "feeding", "покормил", "кормил", "покормить"},
+	"change": {"changed", "change", "changes", "changing", "поменял", "сменил", "заменил"},
+	"clean":  {"cleaned", "clean", "cleans", "cleaning", "почистил", "убрал", "убирал", "помыл", "мыл"},
+	"take":   {"took", "take", "takes", "taking", "принял", "выпил", "пил", "съел", "ел"},
+	"walk":   {"walked", "walk", "walks", "walking", "гулял", "выгулял", "прогулка"},
+	"water":  {"watered", "water", "waters", "watering", "полил", "поливал"},
+}
+
+// invertLexicon builds a fast map from any variant → canonical action.
+var variantToAction map[string]string
+
+func init() {
+	variantToAction = make(map[string]string)
+	for canonical, variants := range actionLexicon {
+		for _, v := range variants {
+			variantToAction[v] = canonical
+		}
+	}
+}
+
+// Extract attempts to normalize a fact (key + value) into an Event.
+// Returns nil when the fact doesn't describe a recognizable action —
+// structured JSON values, empty values, and unrecognized actions all
+// produce no event (false negative by design).
+//
+// Rules:
+//   - If value starts with '{' or '[' (JSON), skip — it's structured data,
+//     not an action statement.
+//   - The value (trimmed, lowered) is looked up in the action lexicon.
+//   - The key (trimmed, lowered) becomes the object.
+//   - Both action and object must be non-empty.
+func Extract(factID int64, key, value string, ts time.Time) *Event {
+	v := strings.TrimSpace(value)
+	if v == "" {
+		return nil
+	}
+	// Skip structured JSON values — measurements, config, etc.
+	if v[0] == '{' || v[0] == '[' {
+		return nil
+	}
+
+	action, ok := variantToAction[strings.ToLower(v)]
+	if !ok {
+		return nil
+	}
+
+	object := strings.TrimSpace(strings.ToLower(key))
+	if object == "" {
+		return nil
+	}
+
+	return &Event{
+		FactID: factID,
+		Action: action,
+		Object: object,
+		Ts:     ts,
+	}
+}