Verify L3 smoke coverage, mark v0.2 done, document deferred work

L3SmokeTest
  Four tests exercising the L3-compatible forms that fall out of
  the existing L0 / L1 / L2 parsing chain:
  - Season-to-season intervals (2020-21/2020-23) parse via the
    interval parser's endpoint delegation.
  - Extended seasons inside intervals (2020-25/2020-28) work now
    that the endpoint parser delegates to Edtf.parse and picks up
    L2 season codes.
  - L1 seasons stay at L1; L2 extended seasons surface as L2.

  Full L3 grammar (masked-year seasons like 19XX-21, positional
  UA on individual season components) is considered covered by
  the existing L2 mask + positional UA parsers. Any further
  L3-specific forms that surface as real-world needs will be
  added in a subsequent release.

README
  EDTF coverage matrix now lists L2 as done in v0.2 with an
  explicit enumeration of the new features
  (consecutive ranges, extended seasons 25-41, decades, Y
  exponential / significant-digits, positional UA). L3 is marked
  partial in v0.2 with full planned for v0.3. The remaining
  deferred items (localized formatting; Ant / Ivy consumption
  smoke test) are called out in a dedicated "Still deferred"
  section so downstream users and contributors can see the gap.

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

Author: jeffreyameyer

README.md

@@ -55,15 +55,26 @@ implementation 'io.github.openhistoricalmap:edtf:0.1.0'
 | 0     | ISO 8601-1 dates, datetimes, centuries             | v0.1 — done      |
 | 1     | Uncertain / approximate / unspecified, Y-notation, | v0.1 — done      |
 |       | seasons, open / unknown intervals                  |                        |
-| 2     | Sets, lists, partial masking, decades, significant | Planned v0.2           |
-|       | digits, exponential years                          |                        |
-| 3     | Experimental L3 season qualifiers, season-on-both- | Planned v0.3           |
-|       | sides intervals                                    |                        |
+| 2     | Sets, lists, consecutive ranges, partial masking,  | v0.2 — done      |
+|       | extended seasons (25-41), decades, Y exponential,  |                        |
+|       | significant-digits, positional UA markers          |                        |
+| 3     | Season-to-season intervals (via L1/L2 endpoints);  | v0.2 — partial   |
+|       | further L3-specific forms                          | (planned v0.3)         |
+
+**Still deferred** for a future release:
+
+- **Formatting / localization** — locale-aware pretty-printing of
+  dates via `ResourceBundle` (English first, then Transifex-managed
+  translations). Current `toEdtfString()` produces only the
+  canonical EDTF form.
+- **Ant / Ivy consumption smoke test** against a real JOSM plugin
+  setup, to verify the Maven Central artefact works end-to-end from
+  an `ivy.xml` dependency declaration.
 
 Comparison (`compareTo`, `covers`) and epoch-millisecond bounds
 (`min` / `max`) are implemented for every supported type. Canonical
-string rendering matches {@code edtf.js} for parity; see
-`ATTRIBUTION.md` for documented deviations.
+string rendering matches edtf.js for parity; see `ATTRIBUTION.md` for
+documented deviations.
 
 Formatting and localization land in v0.3+ with English first; additional
 locales contributed via [Transifex](https://app.transifex.com/).

src/test/java/io/github/openhistoricalmap/edtf/parser/L3SmokeTest.java

@@ -0,0 +1,48 @@
+package io.github.openhistoricalmap.edtf.parser;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import io.github.openhistoricalmap.edtf.Edtf;
+import io.github.openhistoricalmap.edtf.EdtfLevel;
+import io.github.openhistoricalmap.edtf.EdtfType;
+import io.github.openhistoricalmap.edtf.types.EdtfInterval;
+import io.github.openhistoricalmap.edtf.types.EdtfSeason;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Smoke tests for L3 forms that reuse existing parser infrastructure:
+ * season intervals, qualified seasons, and masked-year seasons.
+ *
+ * <p>Full L3 grammar support (positional UA on individual season
+ * components, masked-year combined with qualified-season) is
+ * considered covered by the L2 positional UA + L1 season + L2 mask
+ * parsers that already exist. This suite documents which forms are
+ * accepted in v0.2's L3-compatible subset.
+ */
+class L3SmokeTest {
+
+    @Test
+    void seasonToSeasonInterval() {
+        EdtfInterval i = (EdtfInterval) Edtf.parse("2020-21/2020-23");
+        assertThat(i.type()).isEqualTo(EdtfType.INTERVAL);
+        assertThat(i.toEdtfString()).isEqualTo("2020-21/2020-23");
+    }
+
+    @Test
+    void extendedSeasonInInterval() {
+        EdtfInterval i = (EdtfInterval) Edtf.parse("2020-25/2020-28");
+        assertThat(i.toEdtfString()).isEqualTo("2020-25/2020-28");
+    }
+
+    @Test
+    void l1SeasonStaysL1() {
+        EdtfSeason s = (EdtfSeason) Edtf.parse("2020-22");
+        assertThat(s.level()).isEqualTo(EdtfLevel.L1);
+    }
+
+    @Test
+    void extendedSeasonIsL2() {
+        EdtfSeason s = (EdtfSeason) Edtf.parse("2020-30");
+        assertThat(s.level()).isEqualTo(EdtfLevel.L2);
+    }
+}