docs(defkit): expand definition-builder method tables to match API reference

[jerrinfrancis]

Description of your changes

Brings the four defkit definition-builder doc pages up to parity with the consolidated defkit-reference.html single-page reference, so the method tables users see in the docs list every public builder method instead of a curated subset.

• docs/platform-engineers/defkit/definition-component.md — 14 → 27 methods, grouped under Metadata / Workload / Parameters & Template / Health & Status / Placement / Escape Hatches / Output.
• docs/platform-engineers/defkit/definition-trait.md — 10 → 27 methods, split into Trait-specific (9) and Shared base (18) sections.
• docs/platform-engineers/defkit/definition-policy.md — 3 → 19 methods, split into Policy-specific (2) and Shared base (17); documents PolicyTemplate.Set.
• docs/platform-engineers/defkit/definition-workflowstep.md — 6 → 22 methods, split into step-specific (5) and shared (17); adds WorkflowStepTemplate (6) and BuiltinActionBuilder (5) sub-builder tables.
• Mirrors all four files into versioned_docs/version-v1.11-alpha/platform-engineers/defkit/.

Follow-up to #1421 and #1425. Method names/signatures verified against pkg/definition/defkit/{component,trait,policy,workflow_step}.go in kubevela/kubevela.

I have:

• Read and followed KubeVela's contribution process.
• Update sidebar.js if adding a new page. (No new pages.)
• Run yarn start to ensure the changes has taken effect.

Special notes for your reviewer

First pass of a larger revamp — follow-ups will extend table parity to the parameter / template / helper / collection / patch / validator pages. Opening as draft accordingly. Descriptions lifted from the in-repo defkit-reference.html, lightly trimmed.

---

Summary by cubic

Expands defkit docs to full API parity with the single-page defkit-reference.html, and refactors docs structure (architecture vs integration) while refreshing Quick Start. Adds concise method tables across builders and supporting pages, updates examples, and syncs all changes to versioned_docs/version-v1.11-alpha/.

• New Features

  • Definition builders (Component, Trait, Policy, WorkflowStep): complete method tables; adds WorkflowStepTemplate and BuiltinActionBuilder sub-builders; improved examples.
  • Reference tables added across supporting pages (~350 methods): parameters (scalar/collection/complex + chain), collections API, value expressions, resource/patch builders, template outputs/helpers/trait patch ops, testing, velactx, cluster placement (label conditions + combinators), health/status DSL presets, for-each variants, workflow op builders; ships consolidated defkit-reference.html.

• Refactors

  • Quick Start: prerequisites in a warning box (Go 1.23.8+, CUE v0.14.1+, KubeVela v1.11+); code blocks collapsible; generated CUE example moved after gen-module and updated.
  • Overview streamlined; Architecture focuses on pipeline/contract/health; Integration owns setup (example go.mod with github.com/oam-dev/kubevela v1.11.0, module layout, registration, registry query functions, ToJSON() schema, Register() placement validation note); fixes import path to github.com/oam-dev/kubevela/pkg/definition/defkit.
  • Sidebar: adds definition-register to the Defkit nav and mirrors the change in the versioned sidebar.

^{Written for commit fdfe0de. Summary will update on new commits.}