docs(docs): add wheels deploy guides and CLI reference (starlight-native mdx)

[bpamiri]

Summary

Fills the deployment docs slot deliberately left empty when the v4 guides rewrite shipped (#2169). The Kamal-based wheels deploy port (#2187) is now documented for end users in Starlight-native MDX under web/sites/guides/src/content/docs/v4-0-0-snapshot/.

Deployment guides (7 files under deployment/):

• index.mdx rewrite — replaces the "no wheels deploy in 4.0 today" placeholder with a landing page covering the Kamal lineage, when to reach for the tool vs. alternatives, and the zero-downtime rollover story.
• first-deploy.mdx — guided tutorial from wheels deploy init → wheels deploy with Starlight <Steps>.
• config-reference.mdx — full deploy.yml schema. Every allowed top-level key was sourced directly from cli/lucli/services/deploy/config/Validator.cfc on this branch.
• accessories.mdx, secrets.mdx, hooks.mdx — topic-focused how-tos.
• migrating-from-kamal.mdx — the ERB-vs-Mustache divergence is called out in a <Aside type="caution"> at the top.

CLI reference (69 files under command-line-tools/commands/deploy/):

• One page per verb across 10 groups (top-level + app/proxy/accessory/build/registry/server/prune/lock/secrets). Each page carries frontmatter, synopsis, flags table, behavior paragraph, and 1-2 examples. Behavior is sourced directly from the *Cli.cfc files on develop — e.g. the Phase 2 marker-file app live/app maintenance implementation is documented honestly rather than as full proxy-native maintenance.

Sidebar (src/sidebars/v4-0-0-snapshot.json):

• Deployment & Operations: 6 new items promoted to the top; existing production-config, docker-deployment, vm-deployment, security-hardening, observability-and-logging entries retained below unchanged.
• CLI Reference: new "Deploy Commands" subsection with collapsible per-verb-group leaves.

Test plan

• cd web && pnpm --filter @wheels-dev/site-guides build — green. 415 pages built; all 76 new pages render with correct sidebar position.
• Sidebar JSON validates as JSON (python3 -c "import json; json.load(open(...))").
• Spot-checked frontmatter shape, Starlight component imports, and voice against existing pages (start-here/tutorial/index.mdx, basics/models-and-the-orm.mdx).
• Preview locally with pnpm --filter @wheels-dev/site-guides dev and click through the new sidebar sections.
• Verify migrating-from-kamal.mdx ERB-vs-Mustache callout reads loud enough.

Notes

• Ruby Kamal on-server parity and the deliberate Mustache-for-ERB schema divergence follow the spec at docs/superpowers/specs/2026-04-20-wheels-deploy-kamal-port-design.md.
• Per cli/CLAUDE.md:67 the commit does not include a Co-Authored-By trailer.