fix(2-C): wire dedup into poll loop, add conditional fetch

Bug fixes:
1. Wire is_published/mark_published/bump_last_seen into poll() loop
   - Skip already-published items, bump TTL to prevent sweep
   - Mark published after yield to track new items
2. Add conditional fetch support (If-Modified-Since, If-None-Match)
   - Store Last-Modified/ETag from responses
   - Send conditional headers on subsequent requests
   - Handle 304 Not Modified gracefully (return empty list)
3. Document state parsing rationale in docstring
   - Description has structured State: field vs unreliable title prefixes

Tests added:
- test_dedup_in_poll_loop: verify second poll yields 0 for same items
- test_conditional_304_yields_zero: verify 304 returns empty list
- test_conditional_headers_sent_after_first_poll: verify headers sent

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/central/adapters/inciweb.py

@@ -101,6 +101,12 @@ def parse_state_from_description(description: str) -> str | None:
 
     Format: "State: Minnesota" or "State: New Mexico"
     Returns 2-letter state code or None if not found.
+
+    Design note: State is parsed from the description rather than the title
+    because InciWeb titles use unit code prefixes (e.g., "MNMNS Stewart Trail",
+    "CACNP Santa Rosa Island Fire") which are not reliable state indicators.
+    The description has a structured "State: <name>" field that reliably
+    identifies the state for all incidents.
     """
     pattern = r"State:\s*([A-Za-z\s]+?)(?:\n|---|$)"
     match = re.search(pattern, description)
@@ -176,6 +182,10 @@ class InciWebAdapter(SourceAdapter):
         self._session: aiohttp.ClientSession | None = None
         self._db: sqlite3.Connection | None = None
 
+        # Conditional fetch state
+        self._last_modified: str | None = None
+        self._etag: str | None = None
+
         # Parse region from settings
         region_dict = config.settings.get("region")
         if region_dict:
@@ -300,10 +310,25 @@ class InciWebAdapter(SourceAdapter):
         if not self._session:
             raise RuntimeError("Session not initialized")
 
+        # Build request headers with conditional fetch support
         headers = {"User-Agent": "Central/0.4"}
+        if self._last_modified:
+            headers["If-Modified-Since"] = self._last_modified
+        if self._etag:
+            headers["If-None-Match"] = self._etag
 
         async with self._session.get(INCIWEB_RSS_URL, headers=headers) as resp:
+            # Handle 304 Not Modified
+            if resp.status == 304:
+                logger.info("InciWeb not modified")
+                return []
+
             resp.raise_for_status()
+
+            # Capture conditional fetch headers for next request
+            self._last_modified = resp.headers.get("Last-Modified")
+            self._etag = resp.headers.get("ETag")
+
             content = await resp.text()
 
         # Parse RSS XML
@@ -367,6 +392,11 @@ class InciWebAdapter(SourceAdapter):
             if not guid:
                 continue
 
+            # Dedup: skip if already published
+            if self.is_published(guid):
+                self.bump_last_seen(guid)
+                continue
+
             description_html = item.get("description", "")
 
             # Parse coordinates from description
@@ -435,6 +465,7 @@ class InciWebAdapter(SourceAdapter):
             )
 
             yield event
+            self.mark_published(guid)
             events_yielded += 1
 
         # Periodic cleanup of old entries

tests/test_inciweb.py

@@ -448,3 +448,152 @@ class TestInciWebAdapter:
 
         assert adapter.region.north == 50.0
         assert adapter.region.south == 35.0
+
+    @pytest.mark.asyncio
+    async def test_dedup_in_poll_loop(
+        self, mock_config_no_region: AdapterConfig, mock_config_store: MagicMock, cursor_db_path: Path
+    ):
+        """Dedup integration: second poll with same items yields zero events."""
+        from central.adapters.inciweb import InciWebAdapter
+
+        adapter = InciWebAdapter(mock_config_no_region, mock_config_store, cursor_db_path)
+        await adapter.startup()
+
+        # Single-item RSS for clarity
+        single_item_rss = """<?xml version="1.0" encoding="utf-8"?>
+<rss xmlns:dc="http://purl.org/dc/elements/1.1/" version="2.0">
+  <channel>
+    <title>InciWeb</title>
+    <item>
+      <title>Test Fire</title>
+      <link>http://inciweb.wildfire.gov/test</link>
+      <description>State: California</description>
+      <pubDate>Mon, 18 May 2026 09:00:00 EDT</pubDate>
+      <guid isPermaLink="false">DEDUP-TEST-001</guid>
+    </item>
+  </channel>
+</rss>"""
+
+        def make_mock_response():
+            mock_response = AsyncMock()
+            mock_response.status = 200
+            mock_response.raise_for_status = MagicMock()
+            mock_response.text = AsyncMock(return_value=single_item_rss)
+            mock_response.headers = {"Last-Modified": None, "ETag": None}
+            return mock_response
+
+        # First poll: should yield 1 event
+        with patch.object(
+            adapter._session, "get",
+            return_value=AsyncMock(
+                __aenter__=AsyncMock(return_value=make_mock_response()),
+                __aexit__=AsyncMock()
+            )
+        ):
+            events_first = [e async for e in adapter.poll()]
+
+        assert len(events_first) == 1
+        assert events_first[0].data["guid"] == "DEDUP-TEST-001"
+
+        # Verify mark_published was called
+        assert adapter.is_published("DEDUP-TEST-001") is True
+
+        # Second poll: same item should be skipped (dedup)
+        with patch.object(
+            adapter._session, "get",
+            return_value=AsyncMock(
+                __aenter__=AsyncMock(return_value=make_mock_response()),
+                __aexit__=AsyncMock()
+            )
+        ):
+            events_second = [e async for e in adapter.poll()]
+
+        assert len(events_second) == 0  # Dedup prevents re-yield
+
+        await adapter.shutdown()
+
+    @pytest.mark.asyncio
+    async def test_conditional_304_yields_zero(
+        self, mock_config_no_region: AdapterConfig, mock_config_store: MagicMock, cursor_db_path: Path
+    ):
+        """HTTP 304 Not Modified returns empty list and yields zero events."""
+        from central.adapters.inciweb import InciWebAdapter
+
+        adapter = InciWebAdapter(mock_config_no_region, mock_config_store, cursor_db_path)
+        await adapter.startup()
+
+        # Mock 304 response
+        mock_response = AsyncMock()
+        mock_response.status = 304
+        mock_response.raise_for_status = MagicMock()
+
+        with patch.object(
+            adapter._session, "get",
+            return_value=AsyncMock(
+                __aenter__=AsyncMock(return_value=mock_response),
+                __aexit__=AsyncMock()
+            )
+        ):
+            events = [e async for e in adapter.poll()]
+
+        assert len(events) == 0
+
+        await adapter.shutdown()
+
+    @pytest.mark.asyncio
+    async def test_conditional_headers_sent_after_first_poll(
+        self, mock_config_no_region: AdapterConfig, mock_config_store: MagicMock, cursor_db_path: Path
+    ):
+        """Conditional fetch headers sent on second poll after first captures them."""
+        from central.adapters.inciweb import InciWebAdapter
+
+        adapter = InciWebAdapter(mock_config_no_region, mock_config_store, cursor_db_path)
+        await adapter.startup()
+
+        # First response with Last-Modified and ETag
+        first_response = AsyncMock()
+        first_response.status = 200
+        first_response.raise_for_status = MagicMock()
+        first_response.text = AsyncMock(return_value="""<?xml version="1.0"?>
+<rss version="2.0"><channel><title>Test</title></channel></rss>""")
+        first_response.headers = {
+            "Last-Modified": "Tue, 19 May 2026 03:00:00 GMT",
+            "ETag": "\"abc123\"",
+        }
+
+        # Track headers sent on second request
+        captured_headers = {}
+
+        def capture_get(*args, **kwargs):
+            captured_headers.update(kwargs.get("headers", {}))
+            second_response = AsyncMock()
+            second_response.status = 304
+            second_response.raise_for_status = MagicMock()
+            return AsyncMock(
+                __aenter__=AsyncMock(return_value=second_response),
+                __aexit__=AsyncMock()
+            )
+
+        # First poll
+        with patch.object(
+            adapter._session, "get",
+            return_value=AsyncMock(
+                __aenter__=AsyncMock(return_value=first_response),
+                __aexit__=AsyncMock()
+            )
+        ):
+            [e async for e in adapter.poll()]
+
+        # Verify adapter captured the headers
+        assert adapter._last_modified == "Tue, 19 May 2026 03:00:00 GMT"
+        assert adapter._etag == "\"abc123\""
+
+        # Second poll with header capture
+        with patch.object(adapter._session, "get", side_effect=capture_get):
+            [e async for e in adapter.poll()]
+
+        # Verify conditional headers were sent
+        assert captured_headers.get("If-Modified-Since") == "Tue, 19 May 2026 03:00:00 GMT"
+        assert captured_headers.get("If-None-Match") == "\"abc123\""
+
+        await adapter.shutdown()