feat(core): add command, intent, and routing primitives

src/context/weighting.ts

@@ -0,0 +1,73 @@
+import type { Message } from '../models/types.js';
+import { getMessageText } from '../models/media.js';
+
+export interface WeightedMessage {
+  index: number;
+  message: Message;
+  score: number;
+}
+
+const TOOL_OUTCOME_PATTERN = /(tool|command|exit code|stack trace|traceback|error|failed|succeeded|output|result)/i;
+const CORRECTION_PATTERN = /(actually|correction|instead|sorry|to clarify|i meant|wrong)/i;
+const PREFERENCE_PATTERN = /(prefer|preference|always|never|please|timezone|call me|i like|i dislike|do not|don't)/i;
+
+export function scoreMessageImportance(message: Message): number {
+  const text = getMessageText(message).trim();
+  if (text.length === 0) {
+    return 0;
+  }
+
+  let score = 0.1;
+
+  if (TOOL_OUTCOME_PATTERN.test(text)) {
+    score += 0.45;
+  }
+  if (CORRECTION_PATTERN.test(text)) {
+    score += 0.35;
+  }
+  if (PREFERENCE_PATTERN.test(text)) {
+    score += 0.4;
+  }
+  if (text.includes('```')) {
+    score += 0.2;
+  }
+
+  if (message.role === 'user') {
+    score += 0.05;
+  }
+
+  if (text.length > 240) {
+    score += 0.1;
+  }
+
+  return Math.max(0, Math.min(1, score));
+}
+
+export function rankMessagesByImportance(messages: Message[]): WeightedMessage[] {
+  return messages.map((message, index) => {
+    const base = scoreMessageImportance(message);
+    const recencyBoost = messages.length > 1 ? (index / (messages.length - 1)) * 0.08 : 0;
+    return {
+      index,
+      message,
+      score: Math.max(0, Math.min(1, base + recencyBoost)),
+    };
+  });
+}
+
+export function selectImportantMessages(messages: Message[], opts: {
+  threshold: number;
+  maxMessages: number;
+}): WeightedMessage[] {
+  if (messages.length === 0 || opts.maxMessages <= 0) {
+    return [];
+  }
+
+  const ranked = rankMessagesByImportance(messages)
+    .filter(item => item.score >= opts.threshold)
+    .sort((a, b) => b.score - a.score || b.index - a.index)
+    .slice(0, opts.maxMessages)
+    .sort((a, b) => a.index - b.index);
+
+  return ranked;
+}