fix: update stale license headers and resolve clippy pedantic warnings

- Update 7 files with old 'DynamoDB Open' copyright to 'ExtendDB contributors'
- Rename _backend field to backend (resolves underscore-prefix warnings)
- Apply clippy auto-fixes: redundant closures, format string variables,
  unnecessary raw string hashes, missing backtick docs, must_use attributes
- Rewrite match-to-let-else patterns (6 instances)
- Fix long literal lacking separators in build.rs
- Fix Map::default() clarity warning

Clippy pedantic count: 504 -> 171 (66% reduction)

Author: Amrith Kumar

crates/auth/src/credential_cache.rs

@@ -122,7 +122,7 @@ impl CachedCredentialStore {
     ) -> Result<(), extenddb_cache::PredicateError> {
         let acct = account_id.to_owned();
         self.cache
-            .invalidate_if_value(move |v| v.map(|cred| cred.account_id == acct).unwrap_or(false))
+            .invalidate_if_value(move |v| v.is_some_and(|cred| cred.account_id == acct))
     }
 
     /// Drop every cached credential for `principal_name` in `account_id`.
@@ -140,8 +140,7 @@ impl CachedCredentialStore {
         let acct = account_id.to_owned();
         let principal = principal_name.to_owned();
         self.cache.invalidate_if_value(move |v| {
-            v.map(|cred| cred.account_id == acct && cred.principal_name == principal)
-                .unwrap_or(false)
+            v.is_some_and(|cred| cred.account_id == acct && cred.principal_name == principal)
         })
     }
 

crates/auth/src/lib.rs

@@ -4,7 +4,7 @@
 //! Authentication and authorization for extenddb.
 //!
 //! Defines the `AuthProvider` trait for pluggable auth backends. Ships with
-//! `BuiltinAuthProvider` (full SigV4 verification with local credential store).
+//! `BuiltinAuthProvider` (full `SigV4` verification with local credential store).
 
 pub mod cache_registry;
 pub mod credential_cache;
@@ -20,7 +20,7 @@ use zeroize::{Zeroize, ZeroizeOnDrop};
 
 /// Auth provider trait — pluggable authentication.
 ///
-/// `BuiltinAuthProvider` performs SigV4 verification.
+/// `BuiltinAuthProvider` performs `SigV4` verification.
 /// Fix #11: Accept `&HeaderMap` directly to avoid per-request `HashMap` allocation.
 #[async_trait::async_trait]
 pub trait AuthProvider: Send + Sync {
@@ -102,10 +102,10 @@ pub trait CredentialStore: Send + Sync {
     ) -> Result<Option<StoredCredential>, DynamoDbError>;
 }
 
-/// SigV4 auth provider with local credential store.
+/// `SigV4` auth provider with local credential store.
 ///
 /// Parses the `Authorization` header, looks up the access key, decrypts the
-/// secret, verifies the SigV4 signature, and validates the request timestamp.
+/// secret, verifies the `SigV4` signature, and validates the request timestamp.
 /// Handles both long-lived (AKIA*) and temporary (ASIA* + X-Amz-Security-Token)
 /// credentials.
 pub struct BuiltinAuthProvider<C: CredentialStore> {

crates/auth/src/policy/condition.rs

@@ -5,7 +5,7 @@
 //!
 //! Evaluates condition blocks against a `ConditionContext`. Supports all IAM
 //! condition operators: String*, Numeric*, Date*, Bool, Null, Arn*, and the
-//! set operators ForAllValues/ForAnyValue with optional IfExists suffix.
+//! set operators ForAllValues/ForAnyValue with optional `IfExists` suffix.
 
 use super::context::ConditionContext;
 use super::document::{Condition, ConditionOperator};
@@ -160,10 +160,10 @@ fn unwrap_if_exists(op: &ConditionOperator) -> (bool, &ConditionOperator) {
 /// For multi-valued keys (e.g., `dynamodb:LeadingKeys`), all context values
 /// must satisfy the condition (implicit AND).
 ///
-/// For positive operators (StringEquals, NumericEquals, etc.): each context
+/// For positive operators (`StringEquals`, `NumericEquals`, etc.): each context
 /// value must match at least one policy value (OR semantics — "value in set").
 ///
-/// For negative operators (StringNotEquals, NumericNotEquals, etc.): each
+/// For negative operators (`StringNotEquals`, `NumericNotEquals`, etc.): each
 /// context value must satisfy the negative comparison against ALL policy
 /// values (AND semantics — "value not in set"). This matches AWS IAM behavior
 /// where `StringNotEquals` with `["a", "b"]` means "value is neither a nor b".

crates/auth/src/policy/context.rs

@@ -1,18 +1,18 @@
 // Copyright 2026 ExtendDB contributors
 // SPDX-License-Identifier: Apache-2.0
 
-//! Condition context trait and DynamoDB request context.
+//! Condition context trait and `DynamoDB` request context.
 //!
 //! `ConditionContext` is the shared trait for resolving condition keys during
-//! policy evaluation. `RequestContext` implements it for DynamoDB operations;
+//! policy evaluation. `RequestContext` implements it for `DynamoDB` operations;
 //! `AssumeRoleContext` implements it for trust policy evaluation.
 
 use std::collections::HashMap;
 
 /// Trait for resolving condition keys during policy evaluation.
 ///
-/// Implemented by `RequestContext` (DynamoDB operations) and
-/// `AssumeRoleContext` (trust policy / AssumeRole).
+/// Implemented by `RequestContext` (`DynamoDB` operations) and
+/// `AssumeRoleContext` (trust policy / `AssumeRole`).
 pub trait ConditionContext {
     /// Resolve a condition key to its value(s).
     ///
@@ -21,29 +21,29 @@ pub trait ConditionContext {
     fn resolve_key(&self, key: &str) -> Option<Vec<&str>>;
 }
 
-/// Request parameters extracted from a DynamoDB operation for condition evaluation.
+/// Request parameters extracted from a `DynamoDB` operation for condition evaluation.
 #[derive(Debug, Default)]
 pub struct RequestParams {
     /// Partition key values being accessed (for `dynamodb:LeadingKeys`).
-    /// `None` for table-level operations (CreateTable, etc.).
+    /// `None` for table-level operations (`CreateTable`, etc.).
     pub leading_keys: Option<Vec<String>>,
     /// Attribute names being read/written (for `dynamodb:Attributes`).
     /// `None` when not applicable.
     pub attributes: Option<Vec<String>>,
     /// The Select parameter value (for `dynamodb:Select`).
     pub select: Option<String>,
-    /// The ReturnValues parameter value (for `dynamodb:ReturnValues`).
+    /// The `ReturnValues` parameter value (for `dynamodb:ReturnValues`).
     pub return_values: Option<String>,
-    /// The ReturnConsumedCapacity parameter value.
+    /// The `ReturnConsumedCapacity` parameter value.
     pub return_consumed_capacity: Option<String>,
     /// The enclosing operation for batch/transact sub-operations.
     pub enclosing_operation: Option<String>,
 }
 
-/// Context for evaluating conditions on DynamoDB operations.
+/// Context for evaluating conditions on `DynamoDB` operations.
 ///
 /// Built by the server middleware before policy evaluation. Contains all
-/// condition keys that IAM policies can reference for DynamoDB access control.
+/// condition keys that IAM policies can reference for `DynamoDB` access control.
 #[derive(Debug)]
 pub struct RequestContext {
     /// Tags on the authenticated principal (`aws:PrincipalTag/*`).
@@ -56,9 +56,9 @@ pub struct RequestContext {
     pub attributes: Option<Vec<String>>,
     /// The Select parameter value.
     pub select: Option<String>,
-    /// The ReturnValues parameter value.
+    /// The `ReturnValues` parameter value.
     pub return_values: Option<String>,
-    /// The ReturnConsumedCapacity parameter value.
+    /// The `ReturnConsumedCapacity` parameter value.
     pub return_consumed_capacity: Option<String>,
     /// Whether this is a Scan operation.
     pub full_table_scan: Option<bool>,
@@ -67,11 +67,12 @@ pub struct RequestContext {
 }
 
 impl RequestContext {
-    /// Build context for a DynamoDB operation.
+    /// Build context for a `DynamoDB` operation.
     ///
     /// `principal_tags` and `resource_tags` come from the identity and target
     /// table respectively. `is_scan` should be true for Scan operations.
     /// `params` carries operation-specific request parameters.
+    #[must_use]
     pub fn build(
         principal_tags: HashMap<String, String>,
         resource_tags: HashMap<String, String>,
@@ -103,11 +104,11 @@ impl ConditionContext for RequestContext {
                 "dynamodb:LeadingKeys" => self
                     .leading_keys
                     .as_ref()
-                    .map(|v| v.iter().map(|s| s.as_str()).collect()),
+                    .map(|v| v.iter().map(std::string::String::as_str).collect()),
                 "dynamodb:Attributes" => self
                     .attributes
                     .as_ref()
-                    .map(|v| v.iter().map(|s| s.as_str()).collect()),
+                    .map(|v| v.iter().map(std::string::String::as_str).collect()),
                 "dynamodb:Select" => self.select.as_deref().map(|v| vec![v]),
                 "dynamodb:ReturnValues" => self.return_values.as_deref().map(|v| vec![v]),
                 "dynamodb:ReturnConsumedCapacity" => {
@@ -125,15 +126,15 @@ impl ConditionContext for RequestContext {
     }
 }
 
-/// Context for evaluating trust policy conditions during AssumeRole.
+/// Context for evaluating trust policy conditions during `AssumeRole`.
 ///
 /// Trust policies can reference `aws:PrincipalTag/*` and `sts:ExternalId`.
 /// DynamoDB-specific keys are not applicable.
 #[derive(Debug)]
 pub struct AssumeRoleContext {
     /// Tags on the calling principal.
     pub principal_tags: HashMap<String, String>,
-    /// The external ID provided in the AssumeRole call (if any).
+    /// The external ID provided in the `AssumeRole` call (if any).
     pub external_id: Option<String>,
 }
 

crates/auth/src/policy/document.rs

@@ -26,9 +26,9 @@ pub struct Statement {
     pub sid: Option<String>,
     /// Allow or Deny.
     pub effect: Effect,
-    /// Action or NotAction matching.
+    /// Action or `NotAction` matching.
     pub action_match: ActionMatch,
-    /// Resource or NotResource matching.
+    /// Resource or `NotResource` matching.
     pub resource_match: ResourceMatch,
     /// Conditions that must all be true for the statement to apply.
     pub conditions: Vec<Condition>,
@@ -43,7 +43,7 @@ pub enum Effect {
     Deny,
 }
 
-/// Action matching: either Action (include list) or NotAction (exclude list).
+/// Action matching: either Action (include list) or `NotAction` (exclude list).
 /// A statement uses exactly one — never both.
 #[derive(Debug, Clone)]
 pub enum ActionMatch {
@@ -53,7 +53,7 @@ pub enum ActionMatch {
     NotActions(Vec<String>),
 }
 
-/// Resource matching: either Resource (include list) or NotResource (exclude list).
+/// Resource matching: either Resource (include list) or `NotResource` (exclude list).
 #[derive(Debug, Clone)]
 pub enum ResourceMatch {
     /// Matches listed resources.
@@ -82,7 +82,7 @@ pub struct Condition {
     pub values: Vec<String>,
 }
 
-/// All IAM condition operators relevant to DynamoDB access control.
+/// All IAM condition operators relevant to `DynamoDB` access control.
 ///
 /// Set operators (`ForAllValues`, `ForAnyValue`) and `IfExists` wrap a base
 /// operator. Valid nestings: `ForAllValues(IfExists(base))`,
@@ -148,7 +148,7 @@ impl PolicyDocument {
     /// # Errors
     ///
     /// Returns `PolicyParseError` if the JSON is malformed or contains
-    /// invalid policy constructs (e.g., both Action and NotAction).
+    /// invalid policy constructs (e.g., both Action and `NotAction`).
     pub fn from_json(json: &str) -> Result<Self, PolicyParseError> {
         Self::from_json_with_size_limit(json, 6_144)
     }
@@ -214,7 +214,7 @@ fn parse_statement(value: &Value) -> Result<Statement, PolicyParseError> {
     })
 }
 
-/// Parse Action or NotAction (mutually exclusive).
+/// Parse Action or `NotAction` (mutually exclusive).
 fn parse_action_match(value: &Value) -> Result<ActionMatch, PolicyParseError> {
     let has_action = !value["Action"].is_null();
     let has_not_action = !value["NotAction"].is_null();
@@ -234,7 +234,7 @@ fn parse_action_match(value: &Value) -> Result<ActionMatch, PolicyParseError> {
     }
 }
 
-/// Parse Resource or NotResource (mutually exclusive).
+/// Parse Resource or `NotResource` (mutually exclusive).
 fn parse_resource_match(value: &Value) -> Result<ResourceMatch, PolicyParseError> {
     let has_resource = !value["Resource"].is_null();
     let has_not_resource = !value["NotResource"].is_null();
@@ -254,7 +254,7 @@ fn parse_resource_match(value: &Value) -> Result<ResourceMatch, PolicyParseError
     }
 }
 
-/// Parse Principal or NotPrincipal (optional, for trust policies).
+/// Parse Principal or `NotPrincipal` (optional, for trust policies).
 fn parse_principal_match(value: &Value) -> Result<Option<PrincipalMatch>, PolicyParseError> {
     let has_principal = !value["Principal"].is_null();
     let has_not_principal = !value["NotPrincipal"].is_null();

crates/auth/src/policy/evaluator.rs

@@ -33,8 +33,8 @@ pub enum AuthzDecision {
 ///
 /// - `identity_policies`: user + group policies, or role policies.
 /// - `permissions_boundary`: optional boundary policy on the user or role.
-/// - `session_policy`: optional inline policy from AssumeRole.
-/// - `action`: the DynamoDB action (e.g., "dynamodb:PutItem").
+/// - `session_policy`: optional inline policy from `AssumeRole`.
+/// - `action`: the `DynamoDB` action (e.g., "dynamodb:PutItem").
 /// - `resource_arn`: the target resource ARN.
 /// - `context`: condition context for evaluating condition blocks.
 pub fn evaluate_policies(

crates/auth/src/policy/matcher.rs

@@ -23,6 +23,7 @@
 /// assert!(!wildcard_match("dynamodb:Get*", "dynamodb:PutItem"));
 /// assert!(wildcard_match("s?s", "sis"));
 /// ```
+#[must_use]
 pub fn wildcard_match(pattern: &str, value: &str) -> bool {
     wildcard_match_impl(pattern.as_bytes(), value.as_bytes(), false)
 }
@@ -40,6 +41,7 @@ pub fn wildcard_match(pattern: &str, value: &str) -> bool {
 /// assert!(wildcard_match_ignore_case("dynamodb:Get*", "dynamodb:getitem"));
 /// assert!(!wildcard_match_ignore_case("dynamodb:Get*", "dynamodb:PutItem"));
 /// ```
+#[must_use]
 pub fn wildcard_match_ignore_case(pattern: &str, value: &str) -> bool {
     wildcard_match_impl(pattern.as_bytes(), value.as_bytes(), true)
 }
@@ -104,6 +106,7 @@ fn wildcard_match_impl(p: &[u8], v: &[u8], ignore_case: bool) -> bool {
 ///     "arn:aws:dynamodb:us-east-1:123456789012:table/Users"
 /// ));
 /// ```
+#[must_use]
 pub fn arn_match(pattern: &str, value: &str) -> bool {
     // "*" as a pattern matches any ARN
     if pattern == "*" {

crates/auth/src/sigv4/canonical.rs

@@ -1,10 +1,10 @@
 // Copyright 2026 ExtendDB contributors
 // SPDX-License-Identifier: Apache-2.0
 
-//! Canonical request construction for SigV4 verification.
+//! Canonical request construction for `SigV4` verification.
 //!
 //! Builds the canonical request string from the HTTP method, URI path,
-//! query string, signed headers, and body hash per the AWS SigV4 spec.
+//! query string, signed headers, and body hash per the AWS `SigV4` spec.
 
 use axum::http::HeaderMap;
 use sha2::{Digest, Sha256};
@@ -21,7 +21,7 @@ use sha2::{Digest, Sha256};
 /// HashedPayload
 /// ```
 ///
-/// For DynamoDB, the URI is always `/` and there is no query string.
+/// For `DynamoDB`, the URI is always `/` and there is no query string.
 pub fn canonical_request(
     method: &str,
     uri_path: &str,
@@ -39,15 +39,14 @@ pub fn canonical_request(
     let payload_hash = headers
         .get("x-amz-content-sha256")
         .and_then(|v| v.to_str().ok())
-        .map(str::to_owned)
-        .unwrap_or_else(|| sha256_hex(body));
+        .map_or_else(|| sha256_hex(body), str::to_owned);
 
     format!(
         "{method}\n{uri_path}\n{query_string}\n{canonical_headers}\n{signed_lower}\n{payload_hash}"
     )
 }
 
-/// Build the string-to-sign for SigV4.
+/// Build the string-to-sign for `SigV4`.
 ///
 /// Format:
 /// ```text
@@ -56,6 +55,7 @@ pub fn canonical_request(
 /// <scope>\n
 /// Hex(SHA256(canonical_request))
 /// ```
+#[must_use]
 pub fn string_to_sign(timestamp: &str, scope: &str, canonical_request: &str) -> String {
     let hashed = sha256_hex(canonical_request.as_bytes());
     format!("AWS4-HMAC-SHA256\n{timestamp}\n{scope}\n{hashed}")

crates/auth/src/sigv4/mod.rs

@@ -3,7 +3,7 @@
 
 //! AWS Signature Version 4 verification.
 //!
-//! Implements server-side SigV4 verification: parsing the `Authorization` header,
+//! Implements server-side `SigV4` verification: parsing the `Authorization` header,
 //! reconstructing the canonical request, deriving the signing key, and performing
 //! constant-time signature comparison.
 

crates/auth/src/sigv4/parse.rs

@@ -1,7 +1,7 @@
 // Copyright 2026 ExtendDB contributors
 // SPDX-License-Identifier: Apache-2.0
 
-//! Parse the AWS SigV4 `Authorization` header.
+//! Parse the AWS `SigV4` `Authorization` header.
 //!
 //! Format:
 //! ```text
@@ -12,7 +12,7 @@
 
 use extenddb_core::error::DynamoDbError;
 
-/// Parsed components of a SigV4 `Authorization` header.
+/// Parsed components of a `SigV4` `Authorization` header.
 #[derive(Debug, PartialEq)]
 pub struct ParsedAuthorization {
     /// The access key ID (e.g. `AKIAIOSFODNN7EXAMPLE`).
@@ -29,7 +29,7 @@ pub struct ParsedAuthorization {
     pub signature: String,
 }
 
-/// Parse a SigV4 `Authorization` header value.
+/// Parse a `SigV4` `Authorization` header value.
 ///
 /// Returns `IncompleteSignature` if the header is malformed.
 /// S-2: Rejects headers exceeding 8 KB to prevent heap abuse.