feat(reddit): implement Reddit scraping subagent and associated capabilities

- Added a new `reddit` subagent to scrape structured data from Reddit posts, comments, and users.
- Introduced `reddit.scrape` capability for fetching data using URLs and search queries.
- Implemented tools for scraping and parsing Reddit data, including handling pagination and rate limits.
- Created input/output models for the Reddit scraper to define request and response structures.
- Added documentation for the new Reddit scraping functionality and its usage.
- Integrated the Reddit subagent into the existing multi-agent chat framework.

surfsense_backend/tests/unit/capabilities/reddit/scrape/test_executor.py

@@ -0,0 +1,96 @@
+"""``reddit.scrape`` executor: verb input → actor input mapping → typed items.
+
+Boundary mocked: the proprietary scraper (injected fake). NOT mocked: the verb's
+own payload→RedditScrapeInput mapping and the dict→RedditItem wrapping.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from app.capabilities.reddit.scrape.executor import build_scrape_executor
+from app.capabilities.reddit.scrape.schemas import ScrapeInput, ScrapeOutput
+from app.exceptions import ForbiddenError
+from app.proprietary.platforms.reddit import RedditAccessBlockedError, RedditScrapeInput
+
+pytestmark = pytest.mark.unit
+
+
+class _FakeScraper:
+    """Records the actor input + limit it was called with; returns canned items."""
+
+    def __init__(self, items: list[dict]):
+        self._items = items
+        self.calls: list[tuple[RedditScrapeInput, int | None]] = []
+
+    async def __call__(
+        self, actor_input: RedditScrapeInput, *, limit: int | None = None
+    ) -> list[dict]:
+        self.calls.append((actor_input, limit))
+        return self._items
+
+
+async def test_maps_urls_to_start_urls_and_wraps_items():
+    scraper = _FakeScraper([{"dataType": "post", "id": "abc", "title": "Hello"}])
+    execute = build_scrape_executor(scrape_fn=scraper)
+
+    out = await execute(ScrapeInput(urls=["https://www.reddit.com/r/python/"]))
+
+    assert isinstance(out, ScrapeOutput)
+    assert len(out.items) == 1
+    assert out.items[0].id == "abc"
+    assert out.items[0].title == "Hello"
+    assert out.items[0].dataType == "post"
+
+    (actor_input, _limit) = scraper.calls[0]
+    assert [u.url for u in actor_input.startUrls] == ["https://www.reddit.com/r/python/"]
+    assert actor_input.searches == []
+
+
+async def test_forwards_search_queries_and_community():
+    scraper = _FakeScraper([])
+    execute = build_scrape_executor(scrape_fn=scraper)
+
+    await execute(ScrapeInput(search_queries=["a", "b"], community="python"))
+
+    (actor_input, _limit) = scraper.calls[0]
+    assert actor_input.searches == ["a", "b"]
+    assert actor_input.searchCommunityName == "python"
+    assert actor_input.startUrls == []
+
+
+async def test_maps_caps_and_passes_limit():
+    scraper = _FakeScraper([])
+    execute = build_scrape_executor(scrape_fn=scraper)
+
+    await execute(
+        ScrapeInput(
+            search_queries=["x"],
+            max_items=25,
+            max_posts=7,
+            max_comments=3,
+            skip_comments=True,
+            sort="top",
+            time_filter="week",
+        )
+    )
+
+    (actor_input, limit) = scraper.calls[0]
+    assert actor_input.maxItems == 25
+    assert actor_input.maxPostCount == 7
+    assert actor_input.maxComments == 3
+    assert actor_input.skipComments is True
+    assert actor_input.sort == "top"
+    assert actor_input.time == "week"
+    # The outer collection limit is the caller's total-item cap.
+    assert limit == 25
+
+
+async def test_access_blocked_maps_to_forbidden():
+    async def _blocked(actor_input: RedditScrapeInput, *, limit: int | None = None):
+        raise RedditAccessBlockedError("all IPs refused")
+
+    execute = build_scrape_executor(scrape_fn=_blocked)
+
+    with pytest.raises(ForbiddenError):
+        await execute(ScrapeInput(search_queries=["x"]))

surfsense_backend/tests/unit/capabilities/reddit/scrape/test_schemas.py

@@ -0,0 +1,51 @@
+"""``reddit.scrape`` input guards: a source is required and the batch is bounded."""
+
+from __future__ import annotations
+
+import pytest
+from pydantic import ValidationError
+
+from app.capabilities.reddit.scrape.schemas import (
+    MAX_REDDIT_ITEMS,
+    MAX_REDDIT_SOURCES,
+    ScrapeInput,
+)
+
+pytestmark = pytest.mark.unit
+
+
+def test_rejects_input_with_no_source():
+    with pytest.raises(ValidationError):
+        ScrapeInput()
+
+
+def test_accepts_urls_only():
+    payload = ScrapeInput(urls=["https://www.reddit.com/r/python/"])
+    assert payload.search_queries == []
+
+
+def test_accepts_search_queries_only():
+    payload = ScrapeInput(search_queries=["notebooklm alternative"])
+    assert payload.urls == []
+
+
+def test_accepts_community_only():
+    payload = ScrapeInput(community="python")
+    assert payload.community == "python"
+
+
+def test_defaults_and_bounds():
+    payload = ScrapeInput(search_queries=["x"])
+    assert payload.max_items == 10
+    assert payload.sort == "new"
+    assert payload.include_nsfw is True
+    with pytest.raises(ValidationError):
+        ScrapeInput(search_queries=["x"], max_items=0)
+    with pytest.raises(ValidationError):
+        ScrapeInput(search_queries=["x"], max_items=MAX_REDDIT_ITEMS + 1)
+
+
+def test_rejects_more_sources_than_the_cap():
+    too_many = [f"https://redd.it/{i}" for i in range(MAX_REDDIT_SOURCES + 1)]
+    with pytest.raises(ValidationError):
+        ScrapeInput(urls=too_many)

surfsense_backend/tests/unit/capabilities/reddit/test_registry.py

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+"""The reddit namespace registers its verb as one Capability the doors/agent read."""
+
+from __future__ import annotations
+
+import pytest
+
+from app.capabilities import (
+    reddit,  # noqa: F401  — importing the namespace registers its verbs
+)
+from app.capabilities.core.store import get_capability
+from app.capabilities.reddit.scrape.schemas import ScrapeInput, ScrapeOutput
+
+pytestmark = pytest.mark.unit
+
+
+def test_reddit_scrape_is_registered_and_free():
+    cap = get_capability("reddit.scrape")
+
+    assert cap.name == "reddit.scrape"
+    assert cap.input_schema is ScrapeInput
+    assert cap.output_schema is ScrapeOutput
+    assert cap.billing_unit is None