Re-curate videos toward preferred channels

Swap 24 tense-guide / grammar-note videos to The Language Tutor's
numbered lesson series where a matching lesson exists, filling the two
remaining gaps (ind_preterito_anterior → Lesson 65, estar-gerund-
progressive → Lesson 113). All 32 TLT picks preserved on this pass.

For the non-TLT slots, prefer BaseLang's beginner lesson series where a
topic-specific video exists: ser-vs-estar, preterite-vs-imperfect,
subjunctive-triggers, object-pronouns, conditional-if-clauses,
tener-expressions, future-vs-ir-a, possessive-adjectives,
irregular-yo-verbs, and stem-changing-verbs.

Retire both Tell Me In Spanish videos (personal-a → castellano4U,
types-of-irregular-verbs → Master IRREGULAR VERBS Complete Lesson).

Generator header note clarifies that "not available on this app" rows
are a transient yt-dlp extraction limit — videos still play when tapped
in the app via the Stream button, which opens youtube.com externally.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Conjuga/Scripts/generate_videos_markdown.py

@@ -196,7 +196,9 @@ def main() -> int:
         "Like counts are often blank because YouTube hides the public count on "
         "most videos for signed-out requests. Titles and durations are pulled "
         "live from YouTube; unavailable entries mean the video has been taken "
-        "down, made private, or region-locked."
+        "down, made private, or region-locked. A few entries marked "
+        "\"not available on this app\" are a transient yt-dlp extraction limit "
+        "— the video itself still plays fine when tapping Stream in the app."
     )
     lines.append("")