Add autocomplete endpoint via EXT:solr suggest page type

GET /search?type=7384&tx_solr[queryString]=<input> answers term
completions from the index (spell field) with document counts as lean
JSON - no page envelope, synonyms apply automatically. Two deliberate
deviations from the shipped example, which predates TYPO3 v14: the
plugin runs as USER_INT (config.no_cache is gone, and a cached USER
would pin the first query's suggestions for every later request), and
showTopResults is off (the top-result shape is hardcoded upstream with
the raw document type and full indexed content). Documented in spec
v1.12 clause 7.16.

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

packages/vitec/Configuration/Sets/Vitecset/setup.typoscript

@@ -549,3 +549,40 @@ plugin.tx_solr.search.faceting {
         }
     }
 }
+
+# =============================================================================
+# Autocomplete endpoint: GET /search?type=7384&tx_solr[queryString]=<input>
+# Lean JSON page type (no page envelope) for type-ahead in the React search
+# field. Response: { suggestions: {term: count}, suggestion, documents[],
+# didSecondSearch }.
+# 10 is deliberately USER_INT, not USER as in the shipped example: the example
+# predates TYPO3 v14 (config.no_cache is gone), and a cached USER would pin
+# the first query's suggestions for every later request.
+# =============================================================================
+tx_solr_suggest = PAGE
+tx_solr_suggest {
+    typeNum = 7384
+    config {
+        disableAllHeaderCode = 1
+        additionalHeaders.10.header = Content-Type: application/json; charset=utf-8
+    }
+
+    10 = USER_INT
+    10 {
+        userFunc = TYPO3\CMS\Extbase\Core\Bootstrap->run
+        extensionName = Solr
+        pluginName = pi_suggest
+        vendorName = ApacheSolrForTypo3
+        controller = Suggest
+        action = suggest
+    }
+}
+
+plugin.tx_solr.suggest = 1
+plugin.tx_solr.suggest {
+    numberOfSuggestions = 8
+    suggestField = spell
+    # term suggestions only: the built-in top-results carry the raw document
+    # type and the full indexed content - too fat and off-contract for type-ahead
+    showTopResults = 0
+}