feat(harness): intentional skips + custom-html-tiny functional test; 4-rung ladder (#6)

Declare intentional skips + custom-html-tiny functional test; 4-rung level ladder

- recipe_meta.EXPECTED_NA = {rung: reason} lists intentionally-skipped rungs; any
  essential rung skipped and not listed is unintentional. Skips still cap the level
  (never inflate). results.json: skips:{intentional,unintentional} + level_cap_rung.
- Level ladder = the four essential rungs (install, upgrade, backup/restore,
  functional; top = L4). integration & recipe-local are optional, not leveled
  (SSO still enforced for the run verdict, unchanged).
- Card shows skipped rungs as INTENTIONAL SKIP (green, reason below) / UNINTENTIONAL
  SKIP (amber); level badge gains an expected/gap? third segment.
- custom-html-tiny: functional serve test (exact-byte round-trip + 404); declares
  backup_restore intentionally skipped (stateless static server).

Independently verified by the adversary: 138 unit tests pass cold; live full-stage
run on custom-html-tiny green (upgrade tier ran; level 2; correct skips/badge);
clean teardown.

tests/unit/test_card.py

@@ -14,7 +14,7 @@ sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "..", "runner")
 from harness import card as C  # noqa: E402
 
 
-def _data(level=4, cap="L5 integration (SSO/OIDC + cross-app) N/A"):
+def _data(level=3, cap="L4 functional (recipe-specific tests) N/A"):
     return {
         "recipe": "uptime-kuma",
         "version": "1.23.0",
@@ -51,6 +51,35 @@ def test_badge_svg_wellformed():
     assert svg.startswith("<svg") and svg.endswith("</svg>")
     assert "level 4" in svg
     assert C.level_color(4) in svg
+    # plain cap (no intent) → two-box badge, no third segment
+    assert "expected" not in svg and "gap?" not in svg
+
+
+def test_badge_svg_differentiates_intentional_vs_unintentional_skip():
+    # an intentional (declared) skip capped the climb → muted "expected" third segment
+    exp = C.level_badge_svg(2, "L3 backup/restore N/A", "intentional")
+    assert "level 2" in exp and "expected" in exp and C.EXPECT_COLOR in exp
+    assert "gap?" not in exp
+    # an unintentional skip (not declared) → amber "gap?" third segment
+    gap = C.level_badge_svg(2, "L3 backup/restore N/A", "unintentional")
+    assert "level 2" in gap and "gap?" in gap and C.GAP_COLOR in gap
+    assert "expected" not in gap
+
+
+def test_skip_rows_intentional_and_unintentional():
+    html_out = C._skip_rows(
+        {"intentional": {"backup_restore": "no persistent data"}, "unintentional": ["functional"]}
+    )
+    # intentional skip: labelled row (muted green) + the reason on its own line
+    assert "intentional skip" in html_out and C.SKIP_GREEN in html_out
+    assert "backup/restore" in html_out and "no persistent data" in html_out
+    # unintentional skip: amber row + prompt to declare/add coverage
+    assert "unintentional skip" in html_out and C.GAP_COLOR in html_out
+    assert "functional" in html_out and "EXPECTED_NA" in html_out
+
+
+def test_skip_rows_empty_when_no_skips():
+    assert C._skip_rows({"intentional": {}, "unintentional": []}) == ""
 
 
 def test_card_html_reports_level_verbatim():