fix(kol): count 'reduce' action in divergence detection (was silently dropped)

kol-v2 added the 'reduce' action (KOL partially trimming a long), but
kol_divergence._POST_LONG/_POST_SHORT predate it, so any post whose ticker
action was 'reduce' was skipped by the 'not in (_POST_LONG|_POST_SHORT)'
guard — the divergence scan never saw it.

That dropped a high-value case: a KOL publicly trimming/taking profit on an
asset while their on-chain wallet is ADDING is exactly the talks-vs-trades
mismatch this module exists to surface. 'reduce' is a short-leaning stance,
so it now joins _POST_SHORT:
  reduce + chain adding   → divergence (long)
  reduce + chain reducing → alignment (short)

72 tests pass.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/services/kol_divergence.py

@@ -15,8 +15,11 @@ Two outcomes:
 Logic:
 
   post side  → action ∈ {buy, bullish}        = LONG intent
-                        {sell, bearish} = SHORT intent
+                        {sell, bearish, reduce} = SHORT intent
                         {mention}              = skip (no clear view)
+                 (reduce = partial profit-take / trimming a long → a
+                  risk-reducing, short-leaning stance. Counting it lets us
+                  catch "publicly trimming BTC but wallet is adding" divergence.)
 
   chain side → change_type ∈ {new_position, increased} = LONG action
                               {decreased, closed}        = SHORT action
@@ -54,8 +57,11 @@ WINDOW_DAYS = 7
 MIN_USD_CHANGE = 10_000
 
 # Post actions that map to a directional view (skip 'mention')
+# 'reduce' (kol-v2: partial profit-take / trimming a long) is a short-leaning
+# stance — include it so a "trimming publicly while accumulating on-chain"
+# mismatch is caught instead of silently dropped.
 _POST_LONG  = {"buy", "bullish"}
-_POST_SHORT = {"sell", "bearish"}
+_POST_SHORT = {"sell", "bearish", "reduce"}
 
 # On-chain actions that map to a direction
 _CHAIN_LONG  = {"new_position", "increased"}