docs(skills): add use-graph, the general entry-point skill

[tylerdavis]

Summary

Adds skills/use-graph/SKILL.md — a general entry-point skill that orients an agent on graph's everyday surface and routes deeper work to the existing skills for progressive context.

• Route-first table: setup → graph-project-setup, plan creation/editing → graph-plan-authoring, CI → graph-github-actions-setup; docs named canonical over all skills.
• 60-second mental model distilled from concepts.mdx: plans as chained tool calls, the single namespaced catalog, the shape cache, human-authored plans never replan, the streams/exit-code contract.
• Covers the run/inspect surface directly: plan list/show/validate/run with input forms and exit-code reading, ask/chat + threads as prototyping that seeds the shape cache, tools/shapes/mcp catalog inspection.
• Authoring reduced to three rules (draft by command, edit never redraft, never hand-edit YAML) with an explicit handoff to graph-plan-authoring.
• Keeps the vocabulary contract: the workbench is the TUI; ask/chat is the agent loop.

Test plan

• Skill follows the sibling format (frontmatter name/description, GitHub-URL cross-references)
• Command surface checked against docs/reference/cli.mdx and docs/getting-started/concepts.mdx
• Docs-drift / review checks pass on this PR

🤖 Generated with Claude Code

[graph-graph]

Note

graph_review_9000 · A pure documentation PR adding a new entry-point skill file that summarizes and routes to existing docs/skills, with no code changes.

At a glance

Pass	Area	Status
1	Stated Intent	🟡 Unverified / Intentional
6	Test Coverage	⚪ N/A
2	Pipeline/Control-Step Invariants	⚪ N/A
3	Template/Shape Engine	⚪ N/A
4	Rust/Async/Storage Footguns	⚪ N/A
5	Plan Composition/Model Routing	⚪ N/A
7	Repo Conventions/Docs Parity	✅ Pass
8	CLI Surface/Copy	⚪ N/A

🧵 0 new · 0 open · 0 resolved this run · 0 declined

🟡 Needs verification / intentional (1)

Stated Intent — The PR body's technical claims (command syntax, exit codes, skill cross-references) cannot be verified against the actual CLI/docs source since those files weren't provided in the diff; the described content matches the added file itself but not necessarily current CLI behavior.

⚪ N/A · ✅ Pass

Test Coverage — Docs-only change; no behavioral code to test.

Pipeline/Control-Step Invariants — No pipeline or control-step code touched.

Template/Shape Engine — No template or shape-inference code touched.

Rust/Async/Storage Footguns — No Rust code in this diff.

Plan Composition/Model Routing — No plan composition, routing, or provider code touched.

Repo Conventions/Docs Parity — New skill file follows the sibling skill format (frontmatter, GitHub-URL cross-references) as claimed; this is itself a docs addition so no separate docs-parity gap applies.

CLI Surface/Copy — No CLI code, help text, or exit-code behavior changed — only prose describing existing behavior.