perf(coding-agent): concurrent skill loading + startup indicator through TUI import

[1Morganmore]

What

Two startup fixes in one branch:

1. Concurrent skill loading — loadSkillsFromDirInternal read every SKILL.md sequentially with readFileSync, serializing disk access at startup (a user with ~110 skills paid ~1.2s cold on this Windows host). It now collects the file work in traversal order and runs the IO-bound reads with Promise.all, preserving skill/diagnostic order exactly. loadSkills/loadSkillsFromDir become async; extendResources, updateSkillsFromPaths, the app-server skills loader, and the agent-session call site await them.
2. Startup indicator through the TUI import — the loading indicator stopped right after createAgentSessionRuntime, before the dynamic import of the interactive-mode module graph (the largest cold-start cost after resource loading), leaving a blank terminal that looked frozen. It now stops only after the import.

QA

• Vitest: test/skills.test.ts (existing 27-case suite adapted to the async API + 1 new canonical-path dedupe case) and test/imagegen-skill-gating.test.ts → 31/31 green (Vitest runs both files).
• packages/coding-agent/changes.md updated with both entries.
• (Note: root bun run check/tsgo full static gates not run locally — this machine cannot build the sibling workspace packages; CI runs them.)

Why it is enough

The refactor changes only WHEN reads happen (parallel, awaited before publish) and keeps the returned order; the adapted original suite is the behavior lock.

STOP WHEN

CI green and one approval.

---

Summary by cubic

Speeds up startup by loading skill files concurrently and keeps the startup indicator spinning through the TUI import so the terminal no longer appears frozen.

• loadSkills and loadSkillsFromDir are now async; all call sites await them, and reload() awaits skill loading so the loaded state is published before it completes.
• Skill file reads run in parallel while preserving skill and diagnostic order.
• The startup indicator stops after the interactive-mode import, inside a finally, so an import failure can't leave the spinner running with the cursor hidden.
• Existing skill tests were adapted to the async API, with a new canonical-path dedupe case added.

^{Written for commit 7eb6b8e. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 8 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="packages/coding-agent/src/core/resource-loader.ts">

<violation number="1" location="packages/coding-agent/src/core/resource-loader.ts:523">
P2: When callers invoke `extendResources()` without awaiting it, newly discovered skills are not available on the next statement. Update every caller and the existing resource-loader tests to await the new Promise-returning API before reading resources.</violation>
</file>

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[cubic-dev-ai]

P2: When callers invoke extendResources() without awaiting it, newly discovered skills are not available on the next statement. Update every caller and the existing resource-loader tests to await the new Promise-returning API before reading resources.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At packages/coding-agent/src/core/resource-loader.ts, line 523:

<comment>When callers invoke `extendResources()` without awaiting it, newly discovered skills are not available on the next statement. Update every caller and the existing resource-loader tests to await the new Promise-returning API before reading resources.</comment>

<file context>
@@ -520,7 +520,7 @@ export class DefaultResourceLoader implements ResourceLoader {
 	}
 
-	extendResources(paths: ResourceExtensionPaths): void {
+	async extendResources(paths: ResourceExtensionPaths): Promise<void> {
 		const skillPaths = this.normalizeExtensionPaths(paths.skillPaths ?? []);
 		const promptPaths = this.normalizeExtensionPaths(paths.promptPaths ?? []);
</file context>

[cubic-dev-ai]

1 issue found across 5 files (changes from recent commits).

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="packages/coding-agent/test/skills.test.ts">

<violation number="1" location="packages/coding-agent/test/skills.test.ts:439">
P3: The new try/finally only wraps the assertions, so if the async loadSkills() call above it rejects (e.g. a read failure), the mkdtempSync() temp directory is never cleaned up. Move the loadSkills() call inside the try so the created dir is always removed.</violation>
</file>

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[cubic-dev-ai]

P3: The new try/finally only wraps the assertions, so if the async loadSkills() call above it rejects (e.g. a read failure), the mkdtempSync() temp directory is never cleaned up. Move the loadSkills() call inside the try so the created dir is always removed.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At packages/coding-agent/test/skills.test.ts, line 439:

<comment>The new try/finally only wraps the assertions, so if the async loadSkills() call above it rejects (e.g. a read failure), the mkdtempSync() temp directory is never cleaned up. Move the loadSkills() call inside the try so the created dir is always removed.</comment>

<file context>
@@ -433,7 +433,11 @@ describe("loadSkills canonical path dedupe", () => {
+		try {
+			expect(skills).toHaveLength(1);
+			expect(skills[0]?.name).toBe("dup-skill");
+		} finally {
+			rmSync(root, { recursive: true, force: true });
+		}
</file context>