docs(references): port style guides, 24 diagram guides, and 9 templates from opencode

All content ported from borealBytes/opencode under Apache-2.0 license with
attribution headers prepended to each file.

- references/markdown_style_guide.md (~733 lines): full markdown formatting,
  citation, collapsible sections, emoji, Mermaid integration, and template
  selection guide
- references/mermaid_style_guide.md (~458 lines): full Mermaid standards —
  emoji set, classDef color palette, accessibility (accTitle/accDescr),
  theme neutrality (no %%{init}), and diagram type selection table
- references/diagrams/ (24 files): per-type exemplars, tips, and templates
  for all Mermaid diagram types
- templates/ (9 files): PR, issue, kanban, ADR, presentation, how-to,
  status report, research paper, project docs

Source: https://github.com/borealBytes/opencode

scientific-skills/markdown-mermaid-writing/references/diagrams/requirement.md

@@ -0,0 +1,88 @@
+<!-- Source: https://github.com/borealBytes/opencode | License: Apache-2.0 | Author: Clayton Young / Superior Byte Works, LLC (Boreal Bytes) -->
+
+# Requirement Diagram
+
+> **Back to [Style Guide](../mermaid_style_guide.md)** — Read the style guide first for emoji, color, and accessibility rules.
+
+**Syntax keyword:** `requirementDiagram`
+**Best for:** System requirements traceability, compliance mapping, formal requirements engineering
+**When NOT to use:** Informal task tracking (use [Kanban](kanban.md)), general relationships (use [ER](er.md))
+
+---
+
+## Exemplar Diagram
+
+```mermaid
+requirementDiagram
+
+    requirement high_availability {
+        id: 1
+        text: System shall maintain 99.9 percent uptime
+        risk: high
+        verifymethod: test
+    }
+
+    requirement data_encryption {
+        id: 2
+        text: All data at rest shall be AES-256 encrypted
+        risk: medium
+        verifymethod: inspection
+    }
+
+    requirement session_timeout {
+        id: 3
+        text: Sessions expire after 30 minutes idle
+        risk: low
+        verifymethod: test
+    }
+
+    element auth_service {
+        type: service
+        docref: auth-service-v2
+    }
+
+    element crypto_module {
+        type: module
+        docref: crypto-lib-v3
+    }
+
+    auth_service - satisfies -> high_availability
+    auth_service - satisfies -> session_timeout
+    crypto_module - satisfies -> data_encryption
+```
+
+---
+
+## Tips
+
+- Each requirement needs: `id`, `text`, `risk`, `verifymethod`
+- **`id` must be numeric** — use `id: 1`, `id: 2`, etc. (dashes like `REQ-001` can cause parse errors)
+- Risk levels: `low`, `medium`, `high` (all lowercase)
+- Verify methods: `analysis`, `inspection`, `test`, `demonstration` (all lowercase)
+- Use `element` for design components that satisfy requirements
+- Relationship types: `- satisfies ->`, `- traces ->`, `- contains ->`, `- derives ->`, `- refines ->`, `- copies ->`
+- Keep to **3–5 requirements** per diagram
+- Avoid special characters in text fields — spell out symbols (e.g., "99.9 percent" not "99.9%")
+- Use 4-space indentation inside `{ }` blocks
+
+---
+
+## Template
+
+```mermaid
+requirementDiagram
+
+    requirement your_requirement {
+        id: 1
+        text: The requirement statement here
+        risk: medium
+        verifymethod: test
+    }
+
+    element your_component {
+        type: service
+        docref: component-ref
+    }
+
+    your_component - satisfies -> your_requirement
+```