fix(csr,ui): deliver component outputs to parent bindings

An output only reaches a parent @binding when the component calls
output.<name>(). Two separate faults meant most of the library never got
there, and both failed silently at each end.

HTML lowercases attribute names, so a parent's @sizeChange registered under
"sizechange" while the component emitted "sizeChange". The lookup missed, fell
through to a DOM dispatch, and the binding was never invoked. That made all 17
camelCase outputs undeliverable -- DataTable.pageChange and .rowClick,
Map.markerClick, ChatBubble.messageClick, LayoutSplitter.sizeChange and the
rest. invokeComponentOutput now falls back to a case-insensitive lookup, and a
csr test fails without it.

Separately, 18 components dispatched hand-built CustomEvents rather than
calling output.*. A bubbling event on the component's own root never reaches a
binding, because parent handlers live in a registry only the output proxy
reads. Card, Footer, Breadcrumb, Accordion, alert, Badge, AnnouncementBar,
AvatarGroup, ToggleCount and InputNumber now emit properly; Marquee, Map,
Timeline, List and SearchBox additionally declare the outputs they were
already firing. Dispatches on window are left alone -- that is how Toaster,
Modal and DataTable signal across component boundaries.

Verified in a browser both ways before and after: an AnnouncementBar
dispatching its own bubbling "dismiss" never reached a page-level @dismiss,
and reached it immediately once it called output.dismiss().

This corrects the audit, which called the LayoutSplitter failure "narrow and
unexplained" and read 32 dead outputs as 16 components needing a rebuild.
"Outputs work elsewhere" was an assumption; the components that worked
happened to use lowercase names and output.*. The dead-output ratchet drops
from 32 to 22, and a new test forbids the raw-CustomEvent pattern outright.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/ui-library-audit-2026-08-08.md

@@ -29,30 +29,58 @@ Two mistakes worth recording, because both nearly became wrong conclusions:
 - The semantic token spread sat _after_ the primary and secondary palette
   entries, so it would have overridden them. It now sits before.
 
+## Correction: outputs, and what was actually wrong
+
+The first version of this audit called the LayoutSplitter output failure
+"narrow and unexplained" and treated 32 dead outputs as 16 components needing a
+rebuild. Both were wrong, and the real cause was found by binding a page
+handler to a component in a browser and watching what arrived.
+
+**Two distinct faults were hiding behind one symptom.**
+
+_Emitting the wrong way._ An output only reaches a parent `@binding` when the
+component calls `output.<name>()`. The runtime resolves parent handlers from a
+registry that only `invokeComponentOutput` reads, so a component that builds
+its own `CustomEvent` — even a bubbling one, dispatched on its own root —
+emits into nothing. Eighteen components did exactly that, so their outputs were
+declared, documented, apparently fired, and never delivered. Converting them
+took ten dead outputs off the list and cost no new machinery.
+
+_Case._ HTML lowercases attribute names, so a parent's `@sizeChange` registers
+under `sizechange` while the component emits `sizeChange`. The lookup missed,
+fell through to a DOM dispatch, and the binding was never invoked — silently,
+with no error at either end. **All 17 camelCase outputs in the library were
+undeliverable**, including `DataTable.pageChange` and `DataTable.rowClick`,
+`Map.markerClick`, `ChatBubble.messageClick` and `LayoutSplitter.sizeChange`.
+The runtime now falls back to a case-insensitive lookup, and a test in
+`packages/csr` fails without that fallback.
+
+The lesson worth keeping: "outputs work elsewhere" was an assumption, not a
+measurement. The components that worked happened to use all-lowercase names and
+`output.*`; that coincidence made a framework-wide bug look like one broken
+component.
+
 ## Outstanding, with numbers
 
-**32 outputs across 16 components have no emitter of any kind.** This is the
-bug LayoutSplitter had: the component advertises an output, a caller binds to
-it, and nothing ever fires. Native event names are excluded — the runtime binds
-a DOM-listener fallback on component tags, so `click` and `input` do arrive.
+**22 outputs across 11 components have no emitter of any kind** (was 32 across
+16; see the correction above). The component advertises an output, a caller
+binds to it, and nothing ever fires. Native event names are excluded — the
+runtime binds a DOM-listener fallback on component tags, so `click` and `input`
+do arrive.
 
-| Component                            | Dead outputs                              |
-| ------------------------------------ | ----------------------------------------- |
-| FileUpload                           | upload, progress, success, cancel, remove |
-| ToastNotifications                   | add, dismiss, clear, action               |
-| AdvancedDatePicker                   | open, close, clear                        |
-| Card                                 | action, navigate, dismiss                 |
-| Accordion                            | open, close                               |
-| AdvancedRangeSlider                  | start, end                                |
-| Chart                                | dataPointClick, legendToggle              |
-| Confetti                             | start, complete                           |
-| TreeView                             | expand, collapse                          |
-| AnnouncementBar, Badge, Toast, alert | dismiss                                   |
-| AvatarGroup                          | overflow                                  |
-| CopyMarkup                           | success                                   |
-| Footer                               | action                                    |
+| Component           | Dead outputs                              |
+| ------------------- | ----------------------------------------- |
+| FileUpload          | upload, progress, success, cancel, remove |
+| ToastNotifications  | add, dismiss, clear, action               |
+| AdvancedDatePicker  | open, close, clear                        |
+| AdvancedRangeSlider | start, end                                |
+| Chart               | dataPointClick, legendToggle              |
+| Confetti            | start, complete                           |
+| TreeView            | expand, collapse                          |
+| Toast               | dismiss                                   |
+| CopyMarkup          | success                                   |
 
-A test pins this at 32 as a ceiling that only moves down.
+A test pins this at 22 as a ceiling that only moves down.
 
 **23 components are still on the `wire-next` scaffold pattern** — no style
 block, no functions, and for 19 of them an outputs block they never honour.
@@ -81,11 +109,6 @@ the busiest activity in the library.
 
 ## Known framework defects
 
-- **A component output is not delivered to a parent binding in at least one
-  case.** LayoutSplitter emits `sizeChange` and the component genuinely fires
-  the event, but `@sizeChange` on the tag is not invoked. Outputs work
-  elsewhere, so this is narrow and unexplained. Renaming away from the native
-  `resize` did not fix it, so the first hypothesis was wrong.
 - **A component tag nested inside another component slot is dropped**, leaving
   only its children.
 - **Component props and slot content render once** and do not track page state,

docs/ui-visual-contract-0.8.json

@@ -2,21 +2,21 @@
   "schemaVersion": 1,
   "releaseLine": "0.8",
   "artifacts": {
-    "packages/ui/components/Accordion.wrn": "e74433d405767edd50e58237ac3986e08e14a893450d712f69679c8361485734",
+    "packages/ui/components/Accordion.wrn": "2b2e756a2197052bbcaf7499d01ec4b68b53a3acaf4524b7ca6424b71ba2e9a3",
     "packages/ui/components/AdvancedDatePicker.wrn": "b9b5b08e9464544837a5400bbf9a2cb25724fac037fe196a219b42e5841ad672",
     "packages/ui/components/AdvancedRangeSlider.wrn": "e78b5cf825503d0cd306c6e490d71317ee3db1844882d13b500df1f7f1c408e1",
     "packages/ui/components/AdvancedSelect.wrn": "29d43f8019a3e0e98af7cf12440f41523665535a39a973441b4faea78e67114a",
-    "packages/ui/components/AnnouncementBar.wrn": "5946ef5eb646f7414056f59d9cfe14680aa3c935acc9a1ca6528dc53b23caa48",
+    "packages/ui/components/AnnouncementBar.wrn": "903bfd9421a7350c923ace3315cedc5763fe3e6b7b54b660a0f26281d46a8754",
     "packages/ui/components/AuthForm.wrn": "496d240090269e69679e01cda3b071c012ec4e925a7c01ae883d25e359e381e1",
     "packages/ui/components/AuthSplitLayout.wrn": "72b82495dd14d40a2d594ccdcf3adc925d1567c155750fb1072347b8845aab7b",
-    "packages/ui/components/AvatarGroup.wrn": "9c583f567213f8e1ad4506a7d2abc3fb462d11679fd2196d3828030f28a28964",
+    "packages/ui/components/AvatarGroup.wrn": "66f3d211b7658ca5193c750d0ccb3e392185038d8960d3206f6e8a249e10214e",
     "packages/ui/components/BackToTop.wrn": "b12c56ec8b7aabad68cbdc47f4b3237e2c21a61398f0aa51f9add6229b7357cd",
-    "packages/ui/components/Badge.wrn": "6b55b4d85100d605cf168857aec1dc57da62c1f6a0a5cd6dd877023f24b189cc",
+    "packages/ui/components/Badge.wrn": "e96cdcf182ff9834509464bb2fa4c0b041748d3f7671aa46ab489bae6f3d98ae",
     "packages/ui/components/Blockquote.wrn": "6016dd4450de7cbf5c3cb413599baa2e502321e8eedef54439a0df6d0aae8bcb",
-    "packages/ui/components/Breadcrumb.wrn": "df27101d41cf018d55b6909e0399286a4661637140e341c8624615051d485142",
+    "packages/ui/components/Breadcrumb.wrn": "14732e91468f5793ee5da8599f8e40d84ec51c93d660fb0c0056b956ec707850",
     "packages/ui/components/ButtonGroup.wrn": "0d97fbeed531d1d8ef4b59531923b47b34100d0de71d7bf524b02c668920b3d8",
     "packages/ui/components/CTASection.wrn": "2d2241d4f1018cfd2f8ea1ddd5fa8c8fcb8d1bbb2d4e4498cb9f39ff47a3801c",
-    "packages/ui/components/Card.wrn": "4370df341235819b8a968a3f812209c2e6c29e4471d06578aaa5b577fb6e2dc8",
+    "packages/ui/components/Card.wrn": "457bc546e0b227692ac96ec8f413823463d3cfe9194b6f4847c21a5beee5e8a4",
     "packages/ui/components/Chart.wrn": "841def6b024720bd24898975a1434a1cb39c89e1272d42db431d35d27c98c553",
     "packages/ui/components/ChatBubble.wrn": "0da2bc86830ac712481559bd2fe7214d26f25101f2e8c2e4629e25c004388b52",
     "packages/ui/components/Checkbox.wrn": "45e6046e3ad4acb1c1805b51fd5bf0b95b346d3d53973ededc5e43ea2fd91f70",
@@ -44,23 +44,23 @@
     "packages/ui/components/FileInput.wrn": "8b63811deb90a03763620bedf0d5d3c7d05a20b8ae34292eaface9b756b32ecd",
     "packages/ui/components/FileUpload.wrn": "3346d8978e134c3a1e6bc742201a3fbb0cffb89da40da6fcd856a2adbb971393",
     "packages/ui/components/FileUploadProgress.wrn": "83bcc8558c70fbe0e0670642f65998abd222c235f1031be46bd7c65e6b5c5154",
-    "packages/ui/components/Footer.wrn": "a5dfaa5f9548b7fdd4b556c63428e0ea8d22e5e776a5714d76619999438cf618",
+    "packages/ui/components/Footer.wrn": "d9075d2206af75a1ec4317d7974d47311889400699260e990d672780f43f40bf",
     "packages/ui/components/Grid.wrn": "d089d8657298b4d33993ba4bf7b581f816c65db513d8e48cf1fdd18da19e05a8",
     "packages/ui/components/Hero.wrn": "e4e39dcd59c273192c7e4136f6583279e20b0956bcba4cfbc3f6e01a1fade152",
     "packages/ui/components/HeroActions.wrn": "c5720efe2ce7f6c114eb2ea4ccc3e8102a1099078ba23fd13770eddeb6aec640",
     "packages/ui/components/Image.wrn": "8113441bf90ab0d1d8618d477125ad339021f39e853db89d656c72c492e7a20b",
     "packages/ui/components/Input.wrn": "9ad394eed60f1b05bbd2ccd50dc2de7b78245c52c87afd46055d772c38b7b0c9",
     "packages/ui/components/InputGroup.wrn": "0e23ea541a60e893c9d9e6f95113911ee459468d8d6105bf03aeb55395359123",
-    "packages/ui/components/InputNumber.wrn": "a0aa4f4566bf54ffbef54c99648eab05b5f9870be6ea07639a4ecf3930afb631",
+    "packages/ui/components/InputNumber.wrn": "26936385e9f01ec888a1df61719991aa7a2782305328b02c939d3c2c94e3e8e0",
     "packages/ui/components/Kbd.wrn": "5afaabbb15902bd8fb82cb4155cf6cbfff55600927b54d564d27e2dd8b752386",
-    "packages/ui/components/LayoutSplitter.wrn": "677e2dba6dbf385d8aef14829d785137ea26272a62affcd1839fa74f5145716d",
+    "packages/ui/components/LayoutSplitter.wrn": "6bd6812e364420ed5d3439862116c58d0b011b298679005795bdccdbb7455066",
     "packages/ui/components/LegendIndicator.wrn": "6a7607b27a17196f899132eb952203a1073e4077365a94935f485e700cbac665",
     "packages/ui/components/Link.wrn": "b986abcc66bc0b1c6296f3ff4e560812e35d89cc680d5251d7a3883e68c1d053",
-    "packages/ui/components/List.wrn": "02f960a8e82fa049aac477bac9c1d9371394c86d9c47513138f61bffc79dc7d8",
+    "packages/ui/components/List.wrn": "8cf4505ff6a079feb3b77822d7ed6977a70393dd1e6267f94e75234d3ac215d6",
     "packages/ui/components/ListGroup.wrn": "37e2ec61ceab20ed020a834da03208c493702b41abcf586816e29f2e50d8ee11",
-    "packages/ui/components/Map.wrn": "7b8a0d5412a464fd7cab8977d816542c506d8c5dab8230a3c984c2caee407c91",
+    "packages/ui/components/Map.wrn": "990656db93e1acd73a301a4addaf353afa14430805366d2e5f124b831044afbe",
     "packages/ui/components/MarketingSectionHeader.wrn": "7d6ffcc01a9331474475ea57ca58598be757abd9428b66bdfaf6f3603c5b145b",
-    "packages/ui/components/Marquee.wrn": "b2b35eedf3297ba12ab3776385a9f3eab001027648d87a2a1968f576eee6c025",
+    "packages/ui/components/Marquee.wrn": "3395235807aea43ac10c4d562706e510dac2a32786b4a5d5d73927989ede68df",
     "packages/ui/components/MegaMenu.wrn": "8a9a9b348ca1c5e182914ff55d981a91f47a49c52ef5e5efd8e4cb6e56361a43",
     "packages/ui/components/MetricCard.wrn": "6451182739298691908f68258c0250cce2a78b0dc27c97115579ece30d7d9f92",
     "packages/ui/components/MetricGrid.wrn": "6018a98c10628ed240ed236ed916c0ff60994d192c3aadafd10bc876be0f9364",
@@ -78,7 +78,7 @@
     "packages/ui/components/RangeSlider.wrn": "21eb7a5df0ee2cb5e78f628eb920265998eb9f1a4933d4e5c57db0323fd66b41",
     "packages/ui/components/Rating.wrn": "a2d74dc748fc7d98892684c760518b87fa65411b1102e3611252b87245b3ffcb",
     "packages/ui/components/Scrollspy.wrn": "76d1c17580c8d460f1222ce97585bdcac9779141f2f30d5460c84ff9f75413d8",
-    "packages/ui/components/SearchBox.wrn": "315f54f1feaaa47a815d1e2d7a35b492f09fbfadfc6d37228e1009e19e0652ad",
+    "packages/ui/components/SearchBox.wrn": "4a07358530ffb197d80d816b6ee4335a20812b6bee1e66a845c4075305bee6f7",
     "packages/ui/components/Section.wrn": "33eb8a82a2102229c2b1f64cec497e9e8e70b67adab8dbe396be860fccbb699c",
     "packages/ui/components/SectionHeader.wrn": "8eecf2ea7a93139512260e3d46ca2a1afeb341b8bd46b7c30baa6e2c75e25d10",
     "packages/ui/components/Select.wrn": "7f046bb11b7c2470dae26d91a4b2261c66a40ae054d0e04c69b6748912d1e204",
@@ -93,17 +93,17 @@
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     "packages/ui/components/TimePicker.wrn": "2e8e7a90f6b6069a07e7ffd2725ba1e1031e84d55a4f1254025befbb314fa695",
-    "packages/ui/components/Timeline.wrn": "5708c656eefd12f31c93490075ee482bf527059028844bd58cdcddc88461e2b5",
+    "packages/ui/components/Timeline.wrn": "aec123bf69f6bfa41c3564e4eac18b2a245214dc6905ebd0bf5b69f7c2736ae6",
     "packages/ui/components/Toast.wrn": "f37c584d1c1a66401deb53d915c8ee0c70aaf7baa1d3c297fa74c5bdb914dd1d",
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     "packages/ui/components/Toaster.wrn": "7481ecddde9ed5bf1f448d45a78da7ee0009f84963814bf681735db4e5ab75f9",
-    "packages/ui/components/ToggleCount.wrn": "70a75b2bdcc89103f8ca300ee6d21cd61baf8c6a4aeade9b68d1dc529f77064b",
+    "packages/ui/components/ToggleCount.wrn": "17710fb37fc6953911acec4e80cd95c1202836e9b958ae4ce34c9a9639edae95",
     "packages/ui/components/TogglePassword.wrn": "405a85cbfa3d0ff0185b52d2805fba88497a5f25501f01b2438ed3a28591a38d",
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-    "packages/ui/components/alert.wrn": "a6020b3fbf02481f76cea4cfa563a7165c7ccc2920492f6f6b79e98cbf2cf0fa",
+    "packages/ui/components/alert.wrn": "3f4c4c90c2b5a00a13d0fa1e7e48e4898869dd27a50ff412a51d7bcc87a0baac",
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     "packages/ui/components/button.wrn": "647af3918142fd9151e46555345532980633cc3677ec26d0940c253ea789bc31",
     "packages/ui/components/carousel.wrn": "37bdde82de59e90cf02c9fed0ee11f5ddd2979246932701dad9412c4fd358a6a",