Phase 2: add settings types — SPEC §7.3 contract and defaults.

Defines SkillReinjectSettings and default values so read/merge/effective
helpers share one source of truth.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/settings.ts

@@ -0,0 +1,25 @@
+import type { AutoCompactIntegration } from "./state";
+
+/** Global/project skillReinject.* settings (SPEC §7.3). */
+export interface SkillReinjectSettings {
+	enabled: boolean;
+	trackReadPaths: boolean;
+	triggerTurn: boolean;
+	reinjectOnManualCompaction: boolean;
+	autoCompactIntegration: AutoCompactIntegration;
+	suffix: string;
+}
+
+/** Defaults from SPEC §7.3 — extension off until explicitly enabled. */
+export const DEFAULT_SKILL_REINJECT_SETTINGS: Readonly<SkillReinjectSettings> = {
+	enabled: false,
+	trackReadPaths: true,
+	triggerTurn: false,
+	reinjectOnManualCompaction: false,
+	autoCompactIntegration: "auto",
+	suffix: "[skill-reinject] Re-applied after compaction.",
+};
+
+export function createDefaultSettings(): SkillReinjectSettings {
+	return { ...DEFAULT_SKILL_REINJECT_SETTINGS };
+}