feat(python): add native distribution and release infrastructure

- add the Rust-backed Python API with PyStemmer compatibility
- distribute standard compiled models as a separate Python package
- generate model artifacts during builds instead of storing them in Git
- add GitHub release and Pages-backed package index workflows
- add Python tests, benchmarks, documentation, and Gradle integration
- refresh the documentation site, branding, and language benchmarks

tools/run-published-accuracy-benchmarks.sh

@@ -0,0 +1,78 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+report_date="${1:-$(date +%F)}"
+project_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "${project_root}"
+
+classpath_file="build/reports/jmh/jmh-runtime-classpath.txt"
+if [[ ! -s "${classpath_file}" ]]; then
+    printf 'Missing %s; run ./gradlew writeJmhRuntimeClasspath --no-daemon first.\n' "${classpath_file}" >&2
+    exit 1
+fi
+IFS= read -r jmh_classpath < "${classpath_file}"
+
+tmp_dir="${project_root}/build/tmp/jmh"
+report_dir="${project_root}/build/reports/jmh"
+mkdir -p "${tmp_dir}" "${report_dir}"
+
+accuracy_include='^org\.egothor\.stemmer\.benchmark\.(EnglishHunspellStemmerComparisonBenchmarkQuality|EnglishStemmerComparisonBenchmarkQuality|HunspellStemmerComparisonBenchmarkQuality|StemmerComparisonBenchmarkQuality)\..*$'
+coverage_include='^org\.egothor\.stemmer\.benchmark\.EnglishRadixorDictionaryCoverageBenchmark\.exactRootAgreement$'
+accuracy_csv="${report_dir}/stemmer-accuracy-${report_date}.csv"
+
+common_arguments=(
+    -f 0
+    -wi 0
+    -i 1
+    -r 1ms
+    -t 1
+    -bm avgt
+    -tu ns
+    -rf csv
+)
+
+java -Djava.io.tmpdir="${tmp_dir}" -Xms6g -Xmx6g \
+    -cp "${jmh_classpath}" org.openjdk.jmh.Main \
+    "${accuracy_include}" "${common_arguments[@]}" \
+    -rff "${accuracy_csv}" \
+    -o "${report_dir}/stemmer-accuracy-${report_date}.txt"
+
+for candidate in SNOWBALL_CZECH_DIRECT SNOWBALL_PERSIAN_DIRECT SNOWBALL_POLISH_DIRECT; do
+    if ! awk -F, -v candidate="${candidate}" '
+        NR > 1 {
+            value = $8
+            gsub(/^"|"$/, "", value)
+            if (value == candidate) {
+                found = 1
+            }
+        }
+        END { exit found ? 0 : 1 }
+    ' "${accuracy_csv}"; then
+        printf 'Exact-root report omits %s.\n' "${candidate}" >&2
+        exit 1
+    fi
+    for counter in correctMatches evaluatedTokens changedCorrectMatches changedEvaluatedTokens \
+            rootPreservedMatches rootEvaluatedTokens; do
+        if ! awk -F, -v candidate="${candidate}" -v suffix="exactRootAgreement:${counter}" '
+            NR > 1 {
+                benchmark = $1
+                value = $8
+                gsub(/^"|"$/, "", benchmark)
+                gsub(/^"|"$/, "", value)
+                if (value == candidate && benchmark ~ suffix "$") {
+                    found = 1
+                }
+            }
+            END { exit found ? 0 : 1 }
+        ' "${accuracy_csv}"; then
+            printf 'Exact-root report omits %s for %s.\n' "${counter}" "${candidate}" >&2
+            exit 1
+        fi
+    done
+done
+
+java -Djava.io.tmpdir="${tmp_dir}" -Xms6g -Xmx6g \
+    -cp "${jmh_classpath}" org.openjdk.jmh.Main \
+    "${coverage_include}" "${common_arguments[@]}" \
+    -rff "${report_dir}/english-coverage-accuracy-${report_date}.csv" \
+    -o "${report_dir}/english-coverage-accuracy-${report_date}.txt"