Update skills documentation to reflect changes in directory structure and terminology. Replace references to integration tests with blackbox tests across various SKILL.md files and templates. Revise paths in planning and deployment documentation to align with the updated _docs/02_document/ structure. Enhance clarity in task management processes and ensure consistency in terminology throughout the documentation.

.cursor/skills/plan/steps/00_prerequisites.md

@@ -0,0 +1,27 @@
+## Prerequisite Checks (BLOCKING)
+
+Run sequentially before any planning step:
+
+### Prereq 1: Data Gate
+
+1. `_docs/00_problem/acceptance_criteria.md` exists and is non-empty — **STOP if missing**
+2. `_docs/00_problem/restrictions.md` exists and is non-empty — **STOP if missing**
+3. `_docs/00_problem/input_data/` exists and contains at least one data file — **STOP if missing**
+4. `_docs/00_problem/problem.md` exists and is non-empty — **STOP if missing**
+
+All four are mandatory. If any is missing or empty, STOP and ask the user to provide them. If the user cannot provide the required data, planning cannot proceed — just stop.
+
+### Prereq 2: Finalize Solution Draft
+
+Only runs after the Data Gate passes:
+
+1. Scan `_docs/01_solution/` for files matching `solution_draft*.md`
+2. Identify the highest-numbered draft (e.g. `solution_draft06.md`)
+3. **Rename** it to `_docs/01_solution/solution.md`
+4. If `solution.md` already exists, ask the user whether to overwrite or keep existing
+5. Verify `solution.md` is non-empty — **STOP if missing or empty**
+
+### Prereq 3: Workspace Setup
+
+1. Create DOCUMENT_DIR if it does not exist
+2. If DOCUMENT_DIR already contains artifacts, ask user: **resume from last checkpoint or start fresh?**