docs(contexts): prevent hard-wrapped GitHub prose (#113)

## Summary

Add a canonical source-format contract for GitHub Issue, Pull Request,
Discussion, and comment bodies so future contributors and agents do not
hard-wrap remote prose at 80 columns.

Route the contract through `AGENTS.md`, `CLAUDE.md`, both
`quantmind-dev` skill copies, the pull-request workflow, the
development-context index, label guidance, and the Issue/PR templates.
Add regression coverage for every route, template marker, and mirrored
skill reference.

The root cause was generation-side prose wrapping, not Ruff or another
repository lint rule. This keeps Python's 80-column configuration and
repository Markdown formatting unchanged while applying no-wrap
normalization only to GitHub bodies.

## Related Issue

No issue applies; this is a focused contributor-governance fix requested
during Issue maintenance.

## Verification

- `python -m pytest --no-cov -q tests/test_contexts.py` — 6 passed, 50
subtests passed.
- `bash scripts/verify.sh` — Ruff, BasedPyright, 5 import contracts, and
292 tests passed; total coverage 88.55%.
- Commit and pre-push hooks passed without bypassing verification.

## Checklist

- [x] The title uses English Conventional Commit format: `type(scope):
summary`.
- [x] The related issue or design discussion is linked when applicable.
- [x] `bash scripts/verify.sh` passes.
- [x] Every applicable live-network component smoke test passes, or this
PR states why none applies.
- [x] Public behavior has focused tests, an example, and documentation
where applicable.
- [x] The PR is complete, small, and contains no unrelated changes.

No live-network component or runtime public behavior changes; live smoke
tests and a usage example are not applicable.

Author: keli-wen

.agents/skills/quantmind-dev/SKILL.md

@@ -17,7 +17,10 @@ Development workflow for contributing to the QuantMind codebase.
    operation or public-network source.
 4. When creating, updating, or triaging an issue or pull request, use the
    canonical [repository label guidance](../../../contexts/dev/labels.md).
-5. Pick exactly one workflow reference below; do not load the others.
+5. Before writing or editing any GitHub body, follow the canonical
+   [GitHub writing style](../../../contexts/dev/github-writing.md), including
+   its no-hard-wrap rule.
+6. Pick exactly one workflow reference below; do not load the others.
 
 ## Select Workflow
 

.agents/skills/quantmind-dev/references/pull-request.md

@@ -34,7 +34,10 @@ batch input`, `docs(readme): update quick start`.
 
 Written in English (external audiences read it: contributors, search
 indexers, future maintainers). Follow `.github/PULL_REQUEST_TEMPLATE.md`
-and make sure the body covers:
+and the canonical
+[GitHub writing style](../../../../contexts/dev/github-writing.md). Do not
+hard-wrap body prose at 80 columns or another fixed width. Make sure the body
+covers:
 
 1. **What changed and why** — a short summary; link the design discussion
    if one exists.

.claude/skills/quantmind-dev/SKILL.md

@@ -17,7 +17,10 @@ Development workflow for contributing to the QuantMind codebase.
    operation or public-network source.
 4. When creating, updating, or triaging an issue or pull request, use the
    canonical [repository label guidance](../../../contexts/dev/labels.md).
-5. Pick exactly one workflow reference below; do not load the others.
+5. Before writing or editing any GitHub body, follow the canonical
+   [GitHub writing style](../../../contexts/dev/github-writing.md), including
+   its no-hard-wrap rule.
+6. Pick exactly one workflow reference below; do not load the others.
 
 ## Select Workflow
 

.claude/skills/quantmind-dev/references/pull-request.md

@@ -34,7 +34,10 @@ batch input`, `docs(readme): update quick start`.
 
 Written in English (external audiences read it: contributors, search
 indexers, future maintainers). Follow `.github/PULL_REQUEST_TEMPLATE.md`
-and make sure the body covers:
+and the canonical
+[GitHub writing style](../../../../contexts/dev/github-writing.md). Do not
+hard-wrap body prose at 80 columns or another fixed width. Make sure the body
+covers:
 
 1. **What changed and why** — a short summary; link the design discussion
    if one exists.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -6,6 +6,8 @@ labels: ['type: bug']
 assignees: ''
 ---
 
+<!-- github-prose-style: Keep each logical paragraph/list item on one physical line; do not hard-wrap at 80 columns. -->
+
 ## 🐛 Bug Description
 
 <!-- A clear and concise description of what the bug is. -->

.github/ISSUE_TEMPLATE/feature_request.md

@@ -6,6 +6,8 @@ labels: ['type: feature']
 assignees: ''
 ---
 
+<!-- github-prose-style: Keep each logical paragraph/list item on one physical line; do not hard-wrap at 80 columns. -->
+
 ## ✨ Feature Summary
 
 <!-- A clear and concise description of the feature you'd like to see implemented. -->

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,3 +1,5 @@
+<!-- github-prose-style: Keep each logical paragraph/list item on one physical line; do not hard-wrap at 80 columns. -->
+
 ## Summary
 
 <!-- What changed and why? Keep this concise and link the design when useful. -->

AGENTS.md

@@ -89,6 +89,9 @@ A new feature ships with a unit test **and** a focused example:
 
 - Commit messages: English, Conventional Commits.
 - PR titles, PR bodies, and issue bodies: English.
+- GitHub Issue, Pull Request, Discussion, and comment body formatting follows
+  the [GitHub writing style](contexts/dev/github-writing.md); never hard-wrap
+  remote prose at 80 columns or another fixed width.
 - Code comments and docstrings: English, Google style.
 
 ## Development Workflows

CLAUDE.md

@@ -90,6 +90,9 @@ A new feature ships with a unit test **and** a focused example:
 
 - Commit messages: English, Conventional Commits.
 - PR titles, PR bodies, and issue bodies: English.
+- GitHub Issue, Pull Request, Discussion, and comment body formatting follows
+  the [GitHub writing style](contexts/dev/github-writing.md); never hard-wrap
+  remote prose at 80 columns or another fixed width.
 - Code comments and docstrings: English, Google style.
 
 ## Development Workflows

contexts/dev/README.md

@@ -8,6 +8,7 @@ canonical source instead of treating this page as a replacement for it.
 | Architecture constraints and module ownership | [`AGENTS.md`](../../AGENTS.md) or [`CLAUDE.md`](../../CLAUDE.md) |
 | Component-development workflow | [`quantmind-dev` component workflow](../../.agents/skills/quantmind-dev/references/develop-components.md) |
 | Issue and pull-request labels | [Repository label guidance](labels.md) |
+| Issue and pull-request body formatting | [GitHub writing style](github-writing.md) |
 | Public operation and source catalog | [`docs/README.md`](../../docs/README.md) |
 | Public operation naming | [Operation naming contract](../../docs/design/en/operations.md) |
 | Component designs | [`docs/design/`](../../docs/design/) |