Add Osaurus tool target + document the division contract (#603)

Tooling: add Osaurus (Anthropic Agent-Skills SKILL.md format) as a conversion
and install target, wired into convert.sh (convert_osaurus + dispatch/valid/all/
parallel lists, --osaurus flag) and install.sh (detect/label/dest/install_osaurus
+ dispatch). Generated output lands in integrations/osaurus/agency-*/SKILL.md and
is gitignored like every other tool's output (regenerate via convert.sh osaurus).

Docs/guardrails — make the division contract discoverable, since it lived only
in scattered script comments and tripped up multiple contributors:
- CONTRIBUTING.md: complete the division list to all 16 (was missing academic/
  gis/sales) and document that divisions.json is the source of truth (CI-checked
  by check-divisions.sh), how to propose a new division, and that strategy/
  (NEXUS playbooks) and integrations/ (generated output) are NOT divisions.
- install.sh: correct the stale "sync with convert.sh / lint-agents.sh" comment —
  install.sh intentionally keeps strategy/ in AGENT_DIRS (filtered at scan time),
  so it is deliberately NOT the same set as the other two.
- .gitignore: ignore integrations/osaurus/agency-*/ (the osaurus output was the
  one tool whose generated files weren't excluded).

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CONTRIBUTING.md

@@ -31,20 +31,34 @@ This project and everyone participating in it is governed by our Code of Conduct
 Have an idea for a specialized agent? Great! Here's how to add one:
 
 1. **Fork the repository**
-2. **Choose the appropriate category** (or propose a new one):
-   - `engineering/` - Software development specialists
+2. **Choose the appropriate division** (one of the 16 — or propose a new one):
+   - `academic/` - Research, scholarship, and domain-expert specialists
    - `design/` - UX/UI and creative specialists
+   - `engineering/` - Software development specialists
    - `finance/` - Financial planning, accounting, and investment specialists
    - `game-development/` - Game design and development specialists
+   - `gis/` - Geospatial, mapping, and spatial-analysis specialists
    - `marketing/` - Growth and marketing specialists
    - `paid-media/` - Paid acquisition and media specialists
    - `product/` - Product management specialists
    - `project-management/` - PM and coordination specialists
-   - `testing/` - QA and testing specialists
+   - `sales/` - Sales, revenue, and deal specialists
    - `security/` - Security architecture, AppSec, pentest, threat intel, and incident response
-   - `support/` - Operations and support specialists
    - `spatial-computing/` - AR/VR/XR specialists
    - `specialized/` - Unique specialists that don't fit elsewhere
+   - `support/` - Operations and support specialists
+   - `testing/` - QA and testing specialists
+
+   > **Divisions are defined by `divisions.json`** (repo root) — the single source of
+   > truth for the division set, validated in CI by `scripts/check-divisions.sh`.
+   > **Proposing a new division** means: create the directory, add an entry to
+   > `divisions.json` (label/icon/color), and add it to `AGENT_DIRS` in both
+   > `scripts/convert.sh` and `scripts/lint-agents.sh`. The check fails the build
+   > unless all of these agree and the directory contains at least one agent file.
+   >
+   > Note: `strategy/` (NEXUS playbooks/runbooks — no agent frontmatter) and
+   > `integrations/` (generated per-tool output from `convert.sh`) are **not**
+   > divisions and must never be added to the division lists.
 
 3. **Create your agent file** following the template below
 4. **Test your agent** in real scenarios