fix: improve upload_artifact error diagnostics and workflow staging instructions

[Copilot]

The api-consumption-report workflow failed 3 consecutive days (runs 6–8) because the AI agent never copies generated charts to the staging directory before calling upload_artifact. The error message provided no hint about what went wrong — just "path does not exist."

Changes

• actions/setup/js/upload_artifact.cjs — When a requested path doesn't exist in the staging directory, the error now lists available files (or states the directory is empty):

  path does not exist in staging directory: charts/api_calls_trend.png.
  The staging directory is empty — did you forget to copy files to /tmp/gh-aw/safeoutputs/upload-artifacts/?
  

• .github/workflows/api-consumption-report.md (Step 5) — Replaced vague "stage each chart" instruction with explicit cp commands, a verification step, and guidance to use flat filenames (not subdirectory paths like charts/api_calls_trend.png)

[Copilot]

Pull request overview

Improves diagnostics and workflow documentation for upload_artifact to prevent/triage failures when expected files aren’t staged into the safe-outputs upload directory.

Changes:

• Enhance upload_artifact missing-path errors to include staged file listings (or an “empty staging dir” hint).
• Update api-consumption-report workflow instructions to explicitly cp chart PNGs into the staging directory and verify with ls.
• Clarify that artifact uploads should reference staged filenames (not charts/... paths) for this workflow.

Show a summary per file

File	Description
actions/setup/js/upload_artifact.cjs	Adds richer error hints (available staged files / empty staging directory guidance) when a requested path is missing.
.github/workflows/api-consumption-report.md	Rewrites Step 5 with explicit staging + verification commands and clearer path usage guidance.

Copilot's findings

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• Files reviewed: 2/2 changed files
• Comments generated: 1

[Copilot]

The hint branch treats a missing staging directory the same as an empty one: listFilesRecursive() returns [] when STAGING_DIR doesn’t exist, so the message says “The staging directory is empty …” even though the directory may be missing. Consider checking fs.existsSync(STAGING_DIR) separately and using a more accurate hint (e.g., distinguish “does not exist” vs “is empty”).

Suggested change

	const available = listFilesRecursive(STAGING_DIR, STAGING_DIR);
	const hint =
	available.length > 0
	? ` Available files: [${available.slice(0, 20).join(", ")}]${available.length > 20 ? ` … and ${available.length - 20} more` : ""}`
	: " The staging directory is empty — did you forget to copy files to " + STAGING_DIR + "?";
	const stagingDirExists = fs.existsSync(STAGING_DIR);
	const available = stagingDirExists ? listFilesRecursive(STAGING_DIR, STAGING_DIR) : [];
	const hint =
	available.length > 0
	? ` Available files: [${available.slice(0, 20).join(", ")}]${available.length > 20 ? ` … and ${available.length - 20} more` : ""}`
	: stagingDirExists
	? " The staging directory is empty — did you forget to copy files to " + STAGING_DIR + "?"
	: " The staging directory does not exist — did you forget to create or populate " + STAGING_DIR + "?";