docs(docs-site): correct and clarify docs against current code

Comprehensive accuracy pass over docs-site verifying every page against
current source. Fixes wrong/stale claims (AniSkip default, YouTube track
selection, Anki sentence-card requirements, immersion schema v18 + SQL
column names, plugin entrypoint, launcher flags, Cloudflare deploy path,
etc.) and fills gaps (watch history, mediaCache.maxHeight, youtubeSubgen,
character-dictionary refresh/eviction, expanded hot-reload lists).

docs-site/jimaku-integration.md

@@ -79,6 +79,7 @@ SubMiner extracts media info from the current video path to pre-fill the search
 
 - **Season + episode patterns:** `S01E03`, `1x03`
 - **Episode-only patterns:** `E03`, `EP03`, or dash-separated numbers like `Title - 03 -`
+- **Season folders:** a parent directory named `Season 2` or `S2` fills in the season when the filename lacks one
 - **Bracket tags:** `[SubGroup]`, `[1080p]`, `[HEVC]` - stripped before title extraction
 - **Year tags:** `(2024)` - stripped
 - **Dots and underscores:** treated as spaces
@@ -94,7 +95,7 @@ Configure `jimaku.apiKey` or `jimaku.apiKeyCommand` in your config. If using `ap
 
 **"Jimaku request failed" or HTTP 429**
 
-The Jimaku API has rate limits. If you see 429 errors, wait for the retry duration shown in the OSD message and try again. An API key provides higher rate limits.
+The Jimaku API has rate limits. If you see 429 errors, wait for the retry duration shown in the OSD message and try again.
 
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