Annotate TokenizerFactory for Java call sites (#400)

Adds `@JvmStatic` to both factory entry points on the
`TokenizerFactory` object (`fromGguf(Map)`, `fromTokenizerJson(String)`).
Same motivation as StableHloConverterFactory in the previous
commit — without the annotation, Java consumers had to navigate
through the Kotlin object's `INSTANCE` marker:

    var tokenizer =
        TokenizerFactory.INSTANCE.fromGguf(ggufFields);

With the annotation they get the idiomatic static form:

    var tokenizer =
        TokenizerFactory.fromGguf(ggufFields);

The factory is the canonical entry point for the new Qwen
byte-level BPE + SentencePiece tokenizers that landed in #463
and #464, so this is a meaningful win for Java consumers of
the upcoming 0.19.0 release — they get Qwen / Llama / Gemma /
TinyLlama tokenization without any Kotlin-specific interop
glue.

Verified across jvmTest, compileKotlinWasmJs, and macosArm64Test
for skainet-io-core — no regressions.

Third of five commits polishing the Java / JVM consumption
story for the upcoming 0.19.0 release. See #400.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: michalharakal

skainet-io/skainet-io-core/src/commonMain/kotlin/sk/ainet/io/tokenizer/TokenizerFactory.kt

@@ -3,6 +3,7 @@ package sk.ainet.io.tokenizer
 import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.jsonObject
 import kotlinx.serialization.json.jsonPrimitive
+import kotlin.jvm.JvmStatic
 
 /**
  * Selects the right [Tokenizer] implementation for a model.
@@ -33,6 +34,7 @@ public object TokenizerFactory {
      * `ggufModelMetadata.rawFields` — this keeps `skainet-io-core` free of a
      * dependency on `skainet-io-gguf`.
      */
+    @JvmStatic
     public fun fromGguf(fields: Map<String, Any?>): Tokenizer {
         val model = (fields["tokenizer.ggml.model"] as? String)?.lowercase()
             ?: throw UnsupportedTokenizerException(
@@ -57,6 +59,7 @@ public object TokenizerFactory {
      * to [QwenByteLevelBpeTokenizer]; `"Unigram"` (SentencePiece) and
      * `"WordPiece"` currently throw.
      */
+    @JvmStatic
     public fun fromTokenizerJson(json: String): Tokenizer {
         val root = JSON.parseToJsonElement(json).jsonObject
         val modelType = root["model"]?.jsonObject?.get("type")?.jsonPrimitive?.content