fix(github): match bot actors in comment filters using GraphQL __typename (#1616)

`exclude_comments_by_actor` and `include_comments_by_actor` never matched
any bot. Both the documented `*[bot]` wildcard and exact entries such as
`dependabot[bot]` silently did nothing.

GitHub's GraphQL API returns the bare login for App actors ("dependabot"),
while REST and the GitHub UI append a suffix ("dependabot[bot]"). Filter
patterns are written in the suffixed form, so matching a GraphQL login
against them could never succeed and `actor.endsWith("[bot]")` was dead
code.

Request `__typename` on the Actor-typed author selections and normalize
App actors to their suffixed name via `resolveActorName()` before matching.
Normalizing at the filter boundary fixes the wildcard and exact-match cases
together, and leaves the author names shown in the prompt unchanged.

The existing test mocked `login: "scanner[bot]"`, a payload GraphQL never
produces, which is why the gap was invisible. It now mocks the real shape
(`__typename: "Bot", login: "scanner"`) and fails without this fix.

The commit author selection is left alone: it is a GitCommit, not an Actor.

Fixes #1514

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

test/data-fetcher.test.ts

@@ -1215,7 +1215,10 @@ describe("fetchGitHubData integration with time filtering", () => {
                 {
                   id: "2",
                   databaseId: "2",
-                  author: { login: "scanner[bot]" },
+                  // GraphQL returns the bare login for App actors plus
+                  // __typename: "Bot". It does NOT append a "[bot]" suffix the
+                  // way REST does, so this mirrors a real payload.
+                  author: { __typename: "Bot", login: "scanner" },
                   body: "Pre-trigger bot review",
                   state: "COMMENTED",
                   submittedAt: "2024-01-15T11:00:00Z",