feat(http): size-exceeded error variant

Opting for documenting two floors, one for individual fields
and the other for aggregate. Exceeding either
will fail with `header-error.size-exceeded`.

Resolves #889

Author: ricochet

proposals/cli/wit-0.3.0-draft/deps.lock

@@ -5,8 +5,8 @@ sha512 = "f08a2828b88fc6ddea935af584531c484ad4a7a5f30340265e11e91b2bfe0f81e74a66
 
 [filesystem]
 path = "../../filesystem/wit-0.3.0-draft"
-sha256 = "184861e98785957311bfaab242cdf9e66a9ecca11fe2c493b840c461b2361088"
-sha512 = "50fa8801fc0a2c1ecfa3cea52af57836f98a12bb0a264439c13bbdcc0e269b3b37ade38b903d6ce10594d1f585d02ef993f3f769c4cddeebdfc00bf93734ed25"
+sha256 = "8808ea3adfbc1a025d649b82ddf4f38232ca4377100cfe671d80d5ee37fa3147"
+sha512 = "19f4eb8fa62e96ba37b3ea231af6a3bc396c28f82935018a3322441321936b34fb0e44360b378145fcb681d9fea810745969d8baab02ae6017be1784be8abe45"
 
 [random]
 path = "../../random/wit-0.3.0-draft"
@@ -15,5 +15,5 @@ sha512 = "812ce57aa13ff3128779d41f4dad50714365e4f9cfd2e1b13458a885fa65da05e409f1
 
 [sockets]
 path = "../../sockets/wit-0.3.0-draft"
-sha256 = "985821e86f2643d90b7a100420a44a5a60a6838adcf76fdb90a66255e3926dde"
-sha512 = "9ba1e9456c0dc02800ba738acd382a4113103bed72127396546c5f0ad3d38dd5c8e077443bd508b15f86f6095706907e9cb258cccab37c273b4c597a238987e7"
+sha256 = "0be70fab90ec1d62e620f37f8fc55397222ceb68ca8387eb0503df7173782634"
+sha512 = "997e336258dd3d8d1bf1b27463e77d1dc2160eb13fff899c93b446973f5efbc59448a23279b60568679c08e006a20cc88769ec74d6d30baa4e7a17df0bdb2c30"

proposals/http/wit-0.3.0-draft/deps.lock

@@ -10,13 +10,13 @@ sha256 = "888647625fec3eaaf276cb884e426bc32bfa79ced22955f10eb239df74c8550c"
 sha512 = "f08a2828b88fc6ddea935af584531c484ad4a7a5f30340265e11e91b2bfe0f81e74a660a512f72e5197d60278feccc00534833ebd73868e801859dd31a61bdbb"
 
 [filesystem]
-sha256 = "184861e98785957311bfaab242cdf9e66a9ecca11fe2c493b840c461b2361088"
-sha512 = "50fa8801fc0a2c1ecfa3cea52af57836f98a12bb0a264439c13bbdcc0e269b3b37ade38b903d6ce10594d1f585d02ef993f3f769c4cddeebdfc00bf93734ed25"
+sha256 = "8808ea3adfbc1a025d649b82ddf4f38232ca4377100cfe671d80d5ee37fa3147"
+sha512 = "19f4eb8fa62e96ba37b3ea231af6a3bc396c28f82935018a3322441321936b34fb0e44360b378145fcb681d9fea810745969d8baab02ae6017be1784be8abe45"
 
 [random]
 sha256 = "5794796c909d6656fcbae6bed28265210ca57308a624119ac0a472326a75aa8f"
 sha512 = "812ce57aa13ff3128779d41f4dad50714365e4f9cfd2e1b13458a885fa65da05e409f145deefa25c4a82e0e301a41e2e6572705b35752dc33908d565a73a2e9c"
 
 [sockets]
-sha256 = "985821e86f2643d90b7a100420a44a5a60a6838adcf76fdb90a66255e3926dde"
-sha512 = "9ba1e9456c0dc02800ba738acd382a4113103bed72127396546c5f0ad3d38dd5c8e077443bd508b15f86f6095706907e9cb258cccab37c273b4c597a238987e7"
+sha256 = "0be70fab90ec1d62e620f37f8fc55397222ceb68ca8387eb0503df7173782634"
+sha512 = "997e336258dd3d8d1bf1b27463e77d1dc2160eb13fff899c93b446973f5efbc59448a23279b60568679c08e006a20cc88769ec74d6d30baa4e7a17df0bdb2c30"

proposals/http/wit-0.3.0-draft/types.wit

@@ -116,6 +116,17 @@ interface types {
     /// This error indicates that the operation on the `fields` was not
     /// permitted because the fields are immutable.
     immutable,
+
+    /// This error indicates that the operation would exceed an
+    /// implementation-defined limit on field sizes. This may apply to
+    /// an individual `field-value`, a single `field-name` plus all its
+    /// values, or the total aggregate size of all fields.
+    ///
+    /// Implementations MUST accept individual field values of at least
+    /// 8192 bytes and total aggregate field sections of at least 16384
+    /// bytes. These minimums ensure portability across common HTTP
+    /// servers and match HTTP/2's minimum SETTINGS_MAX_FRAME_SIZE.
+    size-exceeded,
   }
 
   /// This type enumerates the different kinds of errors that may occur when
@@ -158,6 +169,12 @@ interface types {
   /// original casing used to construct or mutate the `fields` resource. The `fields`
   /// resource should use that original casing when serializing the fields for
   /// transport or when returning them from a method.
+  ///
+  /// Implementations may impose limits on individual field values and on total
+  /// aggregate field section size. Operations that would exceed these limits
+  /// fail with `header-error.size-exceeded`. Implementations MUST accept
+  /// individual field values of at least 8192 bytes and total aggregate field
+  /// sections of at least 16384 bytes.
   @since(version = 0.3.0-rc-2026-02-09)
   resource fields {
 
@@ -180,7 +197,8 @@ interface types {
     /// well-formed, so they are represented as a raw list of bytes.
     ///
     /// An error result will be returned if any header or value was
-    /// syntactically invalid, or if a header was forbidden.
+    /// syntactically invalid, if a header was forbidden, or if the
+    /// entries would exceed an implementation size limit.
     from-list: static func(
       entries: list<tuple<field-name,field-value>>
     ) -> result<fields, header-error>;
@@ -199,6 +217,9 @@ interface types {
     /// name, if they have been set.
     ///
     /// Fails with `header-error.immutable` if the `fields` are immutable.
+    ///
+    /// Fails with `header-error.size-exceeded` if the name or values would
+    /// exceed an implementation-defined size limit.
     set: func(name: field-name, value: list<field-value>) -> result<_, header-error>;
 
     /// Delete all values for a name. Does nothing if no values for the name
@@ -219,6 +240,9 @@ interface types {
     /// values for that name.
     ///
     /// Fails with `header-error.immutable` if the `fields` are immutable.
+    ///
+    /// Fails with `header-error.size-exceeded` if the value would exceed
+    /// an implementation-defined size limit.
     append: func(name: field-name, value: field-value) -> result<_, header-error>;
 
     /// Retrieve the full set of names and values in the Fields. Like the