docs: migrate to DocumenterVitepress + docstring audit

[ocots]

Summary

Migrates the CTModels.jl documentation to DocumenterVitepress, following the pattern established in CTBase.jl. Also includes a full docstring audit of all public symbols.

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Documentation infrastructure

• docs/Project.toml: add DocumenterVitepress, LiveServer
• docs/make.jl: switch to MarkdownVitepress format; new navigation structure; deploydocs guarded by bases.txt
• docs/api_reference.jl: refactor to CTBase pattern — modules_config loop for public pages, one unified Internals page, subdirectory="api"
• .github/workflows/Documentation.yml: restrict deployment trigger to stable version tags (v[0-9]+\.[0-9]+\.[0-9]+)
• docs/src/.vitepress/config.mts: inject explicit nav array + remote CT CSS/JS assets (generated by DocumenterVitepress.generate_template)

Guides

• docs/src/getting-started.md: new entry-point guide (installation, mental model, 5-minute walkthrough for OCP building, solution assembly, initial guess)
• docs/src/index.md: fix module overview table (was referencing non-existent CTModels.OCP)
• docs/src/model/index.md: fix layer table + add text language to ASCII pipeline diagram
• docs/src/model/components.md: fix broken reference to non-existent OCP/Validation/ path
• docs/src/model/types_and_traits.md: replace broken local philosophy link with Handbook reference
• docs/src/serialization/index.md: rename page to "Extensions"; add text language to dispatch diagram

Docstring audit

Root cause fixed throughout: all julia-repl examples used unqualified calls (PreModel(), state!(), etc.) that would fail at the REPL since CTModels has no top-level exports. All examples now use CTModels.* qualified calls.

Additional fixes per file:

File	Fix
Building/dynamics.jl	Replace non-standard # Preconditions/# Behavior sections with # Returns/# Throws; remove examples with wrong API signatures
Building/time_dependence.jl	Fix invalid \dot escape → \\dot; standardize sections
Building/constraints.jl	Fix __constraint! example (wrong type Dict() → ConstraintsDictType(), mismatched lb/ub dimensions)
Building/build.jl	Replace two examples using old/wrong API (times!, non-in-place dynamics!) with correct qualified workflow
Building/objective.jl	Add full setup context to example
Building/times.jl	Add missing variable! prerequisite to free-time examples
Solutions/build_solution.jl	Qualify time_grid examples; remove non-standard # Behavior section
Solutions/solution_types.jl	Qualify MultipleTimeGridModel constructor example; remove non-standard # Behavior section
ext/CTModelsJLD.jl	Qualify export_ocp_solution/import_ocp_solution examples
ext/CTModelsJSON.jl	Same as above