Phase 7: add defer inject on before_agent_start — combined skill blocks, clear queue.

Builds one injected custom message from pendingReinject via expandSkill, clears the queue only after content is built successfully.

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

src/reinject.ts

@@ -1,8 +1,10 @@
 import type {
+	BeforeAgentStartEventResult,
 	ExtensionContext,
 	SessionCompactEvent,
 	Skill,
 } from "@earendil-works/pi-coding-agent";
+import { expandSkill } from "./expand.js";
 import {
 	filterSkillsNeedingReinject,
 	getKeptEntries,
@@ -11,6 +13,8 @@ import {
 import type { SkillReinjectSettings } from "./settings.js";
 import type { ExtensionState } from "./state.js";
 
+export const DEFERRED_REINJECT_CUSTOM_TYPE = "skill-reinject:inject";
+
 /** Names still registered in resourceLoader (SPEC §5.2). */
 export function registeredSkillNames(skills: readonly Pick<Skill, "name">[]): ReadonlySet<string> {
 	return new Set(skills.map((skill) => skill.name));
@@ -54,3 +58,60 @@ export function enqueueDeferredReinjectFromCompact(
 		registeredSkills,
 	);
 }
+
+/** Combined skill-block user text for pending names in queue order (SPEC §5.3). */
+export function buildDeferredReinjectContent(
+	pendingNames: readonly string[],
+	state: ExtensionState,
+	settings: SkillReinjectSettings,
+	registeredSkills: readonly Pick<Skill, "name" | "filePath" | "baseDir">[],
+): string {
+	const registeredByName = new Map(registeredSkills.map((skill) => [skill.name, skill]));
+	const blocks: string[] = [];
+	for (const name of pendingNames) {
+		const tracked = state.skills.find((skill) => skill.name === name);
+		const registered = registeredByName.get(name);
+		if (!tracked || !registered) {
+			continue;
+		}
+		blocks.push(
+			expandSkill(
+				{
+					name: tracked.name,
+					filePath: registered.filePath,
+					baseDir: registered.baseDir,
+				},
+				settings.suffix,
+			),
+		);
+	}
+	return blocks.join("\n\n");
+}
+
+/**
+ * Defer path on before_agent_start: inject one combined message, then clear queue (SPEC §6.5.1).
+ * Returns undefined when pendingReinject is empty.
+ */
+export function tryConsumeDeferredReinject(
+	state: ExtensionState,
+	settings: SkillReinjectSettings,
+	registeredSkills: readonly Pick<Skill, "name" | "filePath" | "baseDir">[],
+): BeforeAgentStartEventResult | undefined {
+	if (state.pendingReinject.length === 0) {
+		return undefined;
+	}
+	const pendingNames = [...state.pendingReinject];
+	const content = buildDeferredReinjectContent(pendingNames, state, settings, registeredSkills);
+	if (!content) {
+		state.pendingReinject = [];
+		return undefined;
+	}
+	state.pendingReinject = [];
+	return {
+		message: {
+			customType: DEFERRED_REINJECT_CUSTOM_TYPE,
+			content,
+			display: true,
+		},
+	};
+}