Refactor documentation for splittable artifacts and update references

Updated various documentation files to clarify the handling of splittable artifacts, allowing for folder equivalents of key markdown files when they exceed size limits. Adjusted references in multiple sections to reflect this new structure, ensuring consistency across the research methodology. Enhanced clarity on the saving actions and artifact organization, particularly for `01_source_registry.md`, `02_fact_cards.md`, and `06_component_fit_matrix.md`. This change aims to improve usability and maintainability of the research documentation.

.cursor/skills/research/steps/00_project-integration.md

@@ -63,18 +63,43 @@ RESEARCH_DIR/
     └── source_2.md
 ```
 
+#### Splittable artifacts — Layout convention
+
+The following three artifacts MAY equivalently be a **folder** of the same base name when the single-file form has grown unwieldy (typically ≳ 1000 lines or ≳ 200 KB):
+
+- `01_source_registry.md` ↔ `01_source_registry/`
+- `02_fact_cards.md` ↔ `02_fact_cards/`
+- `06_component_fit_matrix.md` ↔ `06_component_fit_matrix/`
+
+When using the folder form:
+
+- Place a `00_summary.md` index file at the folder root with a short common summary table and the cross-cutting status the single-file form would have carried in its preamble.
+- Split per-entry content into category files (e.g. one file per sub-question or per component): `SQ1_*.md`, `C1_*.md`, etc. Keep entry numbering global across the folder so cross-references like "Source #42" still resolve to exactly one place.
+- Cross-references from outside the folder may point at either `01_source_registry/00_summary.md` (for the index) or directly at the relevant category file.
+
+```
+RESEARCH_DIR/01_source_registry/        # split form (when single-file is too large)
+├── 00_summary.md                       # index + investigation status + compact source table
+├── SQ1_existing_systems.md             # category file
+├── SQ2_canonical_pipeline.md           # category file
+├── C1_vio.md                           # per-component file
+└── ...
+```
+
+Throughout the rest of this skill (other steps, references, templates), the singular `XX.md` form is used as a logical name; treat each occurrence as applying equally to the folder form when the artifact has been split.
+
 ### Save Timing & Content
 
 | Step | Save immediately after completion | Filename |
 |------|-----------------------------------|----------|
 | Mode A Phase 1 | AC & restrictions assessment tables | `00_ac_assessment.md` |
 | Step 0-1 | Question type classification + sub-question list | `00_question_decomposition.md` |
-| Step 2 | Each consulted source link, tier, summary | `01_source_registry.md` |
-| Step 3 | Each fact card (statement + source + confidence) | `02_fact_cards.md` |
+| Step 2 | Each consulted source link, tier, summary | `01_source_registry.md` *(splittable, see convention)* |
+| Step 3 | Each fact card (statement + source + confidence) | `02_fact_cards.md` *(splittable, see convention)* |
 | Step 4 | Selected comparison framework + initial population | `03_comparison_framework.md` |
 | Step 6 | Reasoning process for each dimension | `04_reasoning_chain.md` |
 | Step 7 | Validation scenarios + results + review checklist | `05_validation_log.md` |
-| Step 7.5 | Component exact-fit gate and selection status | `06_component_fit_matrix.md` |
+| Step 7.5 | Component exact-fit gate and selection status | `06_component_fit_matrix.md` *(splittable, see convention)* |
 | Step 8 | Complete solution draft | `OUTPUT_DIR/solution_draft##.md` |
 
 ### Save Principles
@@ -92,12 +117,12 @@ RESEARCH_DIR/
 |------|---------|----------------|
 | `00_ac_assessment.md` | AC & restrictions assessment (Mode A only) | After Phase 1 completion |
 | `00_question_decomposition.md` | Question type, sub-question list | After Step 0-1 completion |
-| `01_source_registry.md` | All source links and summaries | Continuously updated during Step 2 |
-| `02_fact_cards.md` | Extracted facts and sources | Continuously updated during Step 3 |
+| `01_source_registry.md` *(splittable)* | All source links and summaries | Continuously updated during Step 2 |
+| `02_fact_cards.md` *(splittable)* | Extracted facts and sources | Continuously updated during Step 3 |
 | `03_comparison_framework.md` | Selected framework and populated data | After Step 4 completion |
 | `04_reasoning_chain.md` | Fact → conclusion reasoning | After Step 6 completion |
 | `05_validation_log.md` | Use-case validation and review | After Step 7 completion |
-| `06_component_fit_matrix.md` | Exact-fit matrix for every proposed component/tool/pattern with status `Selected` / `Rejected` / `Experimental only` / `Needs user decision` | Before Step 8 deliverable formatting |
+| `06_component_fit_matrix.md` *(splittable)* | Exact-fit matrix for every proposed component/tool/pattern with status `Selected` / `Rejected` / `Experimental only` / `Needs user decision` | Before Step 8 deliverable formatting |
 | `OUTPUT_DIR/solution_draft##.md` | Complete solution draft | After Step 8 completion |
 | `OUTPUT_DIR/tech_stack.md` | Tech stack evaluation and decisions | After Phase 3 (optional) |
 | `OUTPUT_DIR/security_analysis.md` | Threat model and security controls | After Phase 4 (optional) |