SW-212 — Reject empty development scripts during project discovery #394

Summary

The dev resolver accepts any string-valued dev/start/start:backend script, including an empty or whitespace-only value. npm can treat an empty script as a successful no-op, causing stellarforge dev to report a workflow when no development process starts. Reject blank selected scripts before spawning npm.

Workstream

• Workstream: WS-DEV
• Primary scope: src/dev/project.ts; tests/dev-project.test.ts
• Protected surface: No
• Priority: P1
• Difficulty: low
• Proposed points: 100

Acceptance Criteria

• Empty and whitespace-only candidate scripts are not selected.
• If all supported candidates are blank or absent, return actionable validation guidance.
• A valid lower-precedence script is selected when an earlier candidate is blank.
• No subprocess is spawned for an invalid project.
• Existing script-selection precedence remains documented.

Dependencies

None unless noted above.

Out of Scope

• Unrelated architecture or public command-contract changes.
• New runtime dependencies without maintainer approval.
• Mainnet deployment or remote template execution.

Definition of Done

• Acceptance criteria have deterministic regression coverage.
• Security and compatibility boundaries remain intact.
• Supported-platform CI passes.

Labels

• Stellar Wave (do not apply until activation is explicitly authorized)
• type: bug
• area: dev
• priority: P1
• difficulty: low
• points: 100
• workstream: dev

Sequencing and scope note

Sequencing: implement after SW-214 (#396) and SW-215 (#397).