Add company-creator skill for scaffolding agent company packages

Skill guides users through creating Agent Companies spec-conformant
packages, either from scratch (with interview-driven hiring plan) or
by analyzing an existing git repo and wrapping its skills/agents.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.agents/skills/company-creator/references/companies-spec.md

@@ -0,0 +1,144 @@
+# Agent Companies Specification Reference
+
+The normative specification lives at:
+
+- Web: https://agentcompanies.io/specification
+- Local: docs/companies/companies-spec.md
+
+Read the local spec file before generating any package files. The spec defines the canonical format and all frontmatter fields. Below is a quick-reference summary for common authoring tasks.
+
+## Package Kinds
+
+| File       | Kind    | Purpose                                           |
+| ---------- | ------- | ------------------------------------------------- |
+| COMPANY.md | company | Root entrypoint, org boundary and defaults        |
+| TEAM.md    | team    | Reusable org subtree                              |
+| AGENTS.md  | agent   | One role, instructions, and attached skills       |
+| PROJECT.md | project | Planned work grouping                             |
+| TASK.md    | task    | Portable starter task                             |
+| SKILL.md   | skill   | Agent Skills capability package (do not redefine) |
+
+## Directory Layout
+
+```
+company-package/
+├── COMPANY.md
+├── agents/
+│   └── <slug>/AGENTS.md
+├── teams/
+│   └── <slug>/TEAM.md
+├── projects/
+│   └── <slug>/
+│       ├── PROJECT.md
+│       └── tasks/
+│           └── <slug>/TASK.md
+├── tasks/
+│   └── <slug>/TASK.md
+├── skills/
+│   └── <slug>/SKILL.md
+├── assets/
+├── scripts/
+├── references/
+└── .paperclip.yaml          (optional vendor extension)
+```
+
+## Common Frontmatter Fields
+
+```yaml
+schema: agentcompanies/v1
+kind: company | team | agent | project | task
+slug: url-safe-stable-identity
+name: Human Readable Name
+description: Short description for discovery
+version: 0.1.0
+license: MIT
+authors:
+  - name: Jane Doe
+tags: []
+metadata: {}
+sources: []
+```
+
+- `schema` usually appears only at package root
+- `kind` is optional when filename makes it obvious
+- `slug` must be URL-safe and stable
+- exporters should omit empty or default-valued fields
+
+## COMPANY.md Required Fields
+
+```yaml
+name: Company Name
+description: What this company does
+slug: company-slug
+schema: agentcompanies/v1
+```
+
+Optional: `version`, `license`, `authors`, `goals`, `includes`, `requirements.secrets`
+
+## AGENTS.md Key Fields
+
+```yaml
+name: Agent Name
+title: Role Title
+reportsTo: <agent-slug or null>
+skills:
+  - skill-shortname
+```
+
+- Body content is the agent's default instructions
+- Skills resolve by shortname: `skills/<shortname>/SKILL.md`
+- Do not export machine-specific paths or secrets
+
+## TEAM.md Key Fields
+
+```yaml
+name: Team Name
+description: What this team does
+slug: team-slug
+manager: ../agent-slug/AGENTS.md
+includes:
+  - ../agent-slug/AGENTS.md
+  - ../../skills/skill-slug/SKILL.md
+```
+
+## PROJECT.md Key Fields
+
+```yaml
+name: Project Name
+description: What this project delivers
+owner: agent-slug
+```
+
+## TASK.md Key Fields
+
+```yaml
+name: Task Name
+assignee: agent-slug
+project: project-slug
+schedule:
+  timezone: America/Chicago
+  startsAt: 2026-03-16T09:00:00-05:00
+  recurrence:
+    frequency: weekly
+    interval: 1
+    weekdays: [monday]
+    time: { hour: 9, minute: 0 }
+```
+
+## Source References (for external skills/content)
+
+```yaml
+sources:
+  - kind: github-file
+    repo: owner/repo
+    path: path/to/SKILL.md
+    commit: <full-sha>
+    sha256: <hash>
+    attribution: Owner Name
+    license: MIT
+    usage: referenced
+```
+
+Usage modes: `vendored` (bytes included), `referenced` (pointer only), `mirrored` (cached locally)
+
+Default to `referenced` for third-party content.