Fix collection method chaining type analysis

[joetannenbaum]

Summary

Fixes type analysis for method chaining on Illuminate\Support\Collection and Illuminate\Database\Eloquent\Collection — e.g. collect(['a', 'b'])->filter()->first() now correctly resolves to string|null instead of mixed, and collect(['a','b','c'])->map(fn($x) => strlen($x)) resolves to Collection<int, int>.

Root causes fixed

@template-covariant was invisible
Collection uses @template-covariant TValue but PhpDocNode::getTemplateTagValues() only returns @template tags. Added support for @template-covariant in parseTemplateTags().

@extends chain not followed for inherited methods
EloquentCollection<TModel> extends Collection<TKey, TModel>, mapping TValue → TModel. Without following this chain, methods defined on Collection (like first()) saw unresolved TValue when called on an EloquentCollection. Added parseExtendsTags() and resolveExtendsChain() to propagate these mappings.

Method-level @template params resolved as string literals
first() declares @template TFirstDefault at the method level. Without handling this, TFirstDefault resolved to StringType('TFirstDefault') instead of being treated as an unbound template. Added bindMethodLevelTemplateTags() to inject method-level template params into scope.

map() TMapValue not inferred from closure argument
map() declares @template TMapValue bound via callable(TValue, TKey): TMapValue. The return type TMapValue was defaulting to null. Added:

• getCallableParamReturnTemplates() in DocBlockParser — scans @param tags at AST level to find callable params whose return type is an identifier, returning [paramName => templateName]
• bindCallableArgTemplates() in Reflector — resolves the closure/arrow function passed at the matching argument position and binds the template to its return type
• resolveCallableArgReturnTypes() in ResolvesMethodCalls — pre-resolves closure/arrow function arguments before passing to methodReturnType()

@use Trait<Type> bindings not resolved
Builder uses BuildsQueries<TModel> via a @use docblock on the trait use statement. Added resolveUseTraitBindings() and parseTraitUseBindings() to parse these bindings and inject them into the scope.

Literal types not generalized in collect()
collect(['a', 'b', 'c']) was building a type from literal StringType('a') values rather than the generalized StringType. Added generalizeLiteralType() to normalize these.

static/self returned wrong type after chaining
When a method returns static/self, the receiver type (the concrete class with generic bindings) should be cloned — not re-derived from the entity name. Fixed in IdentifierTypeNode::resolve().

Tests

Added tests/Unit/CollectionChainingTest.php with 11 integration tests:

• collect(['a','b','c'])->first() → string|null
• collect(['a','b','c'])->filter()->first() → string|null
• collect(['a','b','c'])->filter() → Collection<int, string>
• collect(['a','b','c'])->map(fn($x) => strlen($x)) → Collection<int, int>
• collect(['a','b','c'])->map(fn($x) => strtoupper($x)) → Collection<int, string>
• User::all()->first() → User|null
• User::all()->filter()->first() → User|null
• User::all()->filter() → EloquentCollection<int, User>
• Post::query()->get()->first() → Post|null
• Post::query()->get()->filter()->first() → Post|null
• Post::query()->get()->filter() → EloquentCollection<int, Post>

All 242 existing tests continue to pass (2 skipped).