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/packet.md

@@ -0,0 +1,55 @@
+<!-- Source: https://github.com/borealBytes/opencode | License: Apache-2.0 | Author: Clayton Young / Superior Byte Works, LLC (Boreal Bytes) -->
+
+# Packet Diagram
+
+> **Back to [Style Guide](../mermaid_style_guide.md)** — Read the style guide first for emoji, color, and accessibility rules.
+
+**Syntax keyword:** `packet-beta`
+**Best for:** Network protocol headers, data structure layouts, binary format documentation, bit-level specifications
+**When NOT to use:** General data models (use [ER](er.md)), system architecture (use [C4](c4.md) or [Architecture](architecture.md))
+
+> ⚠️ **Accessibility:** Packet diagrams do **not** support `accTitle`/`accDescr`. Always place a descriptive _italic_ Markdown paragraph directly above the code block.
+
+---
+
+## Exemplar Diagram
+
+_Packet diagram showing the structure of a simplified TCP header with field sizes in bits:_
+
+```mermaid
+packet-beta
+    0-15: "Source Port"
+    16-31: "Destination Port"
+    32-63: "Sequence Number"
+    64-95: "Acknowledgment Number"
+    96-99: "Data Offset"
+    100-105: "Reserved"
+    106-111: "Flags (URG,ACK,PSH,RST,SYN,FIN)"
+    112-127: "Window Size"
+    128-143: "Checksum"
+    144-159: "Urgent Pointer"
+```
+
+---
+
+## Tips
+
+- Ranges are `start-end:` in bits (0-indexed)
+- Keep field labels concise — abbreviate if needed
+- Use for any fixed-width binary format, not just network packets
+- Row width defaults to 32 bits — fields wrap naturally
+- **Always** pair with a Markdown text description above for screen readers
+
+---
+
+## Template
+
+_Description of the protocol or data format and its field structure:_
+
+```mermaid
+packet-beta
+    0-7: "Field A"
+    8-15: "Field B"
+    16-31: "Field C"
+    32-63: "Field D"
+```