Fix low-severity audit findings across all modules

[ConsoleTVs]

Summary

Fourth and final tier of fixes from the comprehensive security and quality audit. This PR addresses low-severity findings across all modules — code style, doc comments, naming conventions, test consistency, import grouping, and minor ergonomic improvements.

Contract

• Rename abbreviated parameters (k→name, d→fallback) in ParamInt/QueryInt variants
• Standardize doc comments from bulleted parameter lists to concise prose style
• Add t.Parallel() to all test functions across 13 test files
• Add NeedsRehash doc comment on Rehashable interface
• Fix WithTransaction doc wording about nested operations

Router

• Rewrite all doc comments: start with symbol name, end with period, fix typos
• Remove redundant zero-value initializers (pattern: "", parent: nil) in New()
• Rename Record parameter r → request for full-word convention
• Add panic message assertions in dot-dot and empty-method tests
• Remove stale RecordHandler cross-reference

Problem

• Remove unused embed import (no //go:embed directive)
• Fix all doc comments: Problem type interfaces, With/Without copy-on-write, Error/Errors/Unwrap descriptions, MarshalJSON/UnmarshalJSON behavior, Defaulted field enumeration, typo fixes
• Replace make([]error, 0) with var for nil-error fast path
• Use strings.Builder instead of += concatenation in textHandler
• Use httptest.NewRequest in accept_test.go

Framework Core

• Add doc comment on handleError explaining error inspection logic
• Extract StatusClientClosedRequest = 499 constant replacing magic number
• Initialize afterResponseHooks in NewHooks for consistency with other hook slices
• Add mutex doc comment in Hooks struct
• Fix ServerOptions doc to cover all zero-valued fields
• Use t.Context() in handler_test.go for proper test cancellation

Middleware

• Fix import grouping to three groups (stdlib/cosmos/external) in all 7 test files
• Rename abbreviated receiver rs → readerStringer in recover_test.go
• Fix RecoverWith doc to suggest interface pattern instead of referencing unexported type
• Remove redundant 1 * in rate limit CleanupInterval default
• Remove compile-time interface check on test-only testTextMarshaler
• Improve Provide doc with parameter guidance and retrieval example

Session

• Remove redundant sync.Mutex{} zero-value initialization
• Fix informal comment and Regenerate/Delete doc inaccuracies
• Replace string literal "GET" with http.MethodGet in all tests
• Export CacheDriverOptions.Prefix field for external configurability
• Fix import grouping in all test files

Cache

• Fix import grouping to three groups in all files
• Align redis doc comments with memory counterparts (Delete, Has, Forever, Increment, Decrement)
• Remove named return values from redis Pull method
• Document Pull's non-atomic nature in memory implementation

Crypto

• Rename TestItCan* tests to TestAES*/TestChaCha20* naming convention
• Rename abbreviated variables e → encrypter, cypher → ciphertext
• Align ChaCha20 struct field order with AES (key, aead, AdditionalData)
• Add ChaCha20 concurrency safety doc note matching AES
• Fix import grouping in test files

Hash

• Rename TestItCan* tests to TestArgon2*/TestBcrypt* naming convention
• Rename abbreviated variables h → hasher, r → hashed
• Replace manual all-zero byte loops with require.Equal assertions
• Use parenthesized import in argon2.go for consistency
• Fix import grouping in test files

Database

• Fix import grouping to three groups in both source and test files
• Replace &sql.TxOptions{} with nil for idiomatic driver defaults

Event

• Fix import grouping to three groups in all source and test files
• Replace fmt.Sprintf with strconv.FormatUint for subscription IDs
• Use var declarations instead of empty composite literals for zero-value types
• Remove unnecessary var() grouping for single ErrBrokerClosed
• Fix deliverToHandler doc comment accuracy
• Add explicit _ = for discarded Close errors in AMQP broker

Breaking Changes

CacheDriverOptions.Prefix is now exported

What changed: prefix field renamed to Prefix.

Migration: If constructing CacheDriverOptions with struct literal, rename prefix → Prefix.

Why: The struct is exported but the field was unexported, making it unconfigurable by external callers.

StatusClientClosedRequest constant added

What changed: New exported constant StatusClientClosedRequest = 499.

Migration: No migration needed — this is a new export. Callers can optionally use it instead of magic number 499.