Refactor activity system: energy-based probability, manual override, all 5 activity types

- Rewrite utils/activities.py with mood energy-driven activity probability
  (high-energy moods like excited/bubbly show activity ~80-85% of the time,
  low-energy moods like sleepy/melancholy only ~15-25%)
- Add manual override system with 30-min auto-expiry for Web UI control
- Support all 5 Discord activity types: listening, playing, watching,
  competing, streaming (with purple LIVE badge via discord.Streaming)
- Add current activity tracking (get_current_activity)
- Add force=True param to update_bot_presence for on_ready (bot.py)
- Add 4 new API routes for manual override:
  GET/POST/DELETE /activities/current, POST /activities/current/auto
- Expand activities.yaml from 139 to 157 entries, adding watching,
  competing, and streaming entries across 11 moods
- Update Web UI: activity type dropdown with all 5 types, conditional
  URL field for streaming, 'Current Activity' override panel with
  set/clear/auto controls, type-aware icons and labels

bot/activities.yaml

@@ -32,6 +32,11 @@ normal:
     name: 'Hatsune Miku: Project DIVA Future Tone'
     weight: 1
     state: Rhythm Game
+  - type: streaming
+    name: VOCALOID Covers
+    weight: 1
+    state: on YouTube
+    url: https://www.youtube.com/watch?v=CGbYfNq3iZQ
   excited:
   - type: listening
     name: Melt
@@ -65,6 +70,14 @@ normal:
     name: Muse Dash
     weight: 2
     state: Rhythm Game
+  - type: streaming
+    name: rhythm game gameplay
+    weight: 1
+    url: https://www.youtube.com/watch?v=3J8EeHxg3po
+  - type: competing
+    name: Beat Saber Tournament
+    weight: 1
+    state: Ranked
   neutral:
   - type: listening
     name: Miku Miku ni Shite Ageru♪
@@ -94,6 +107,14 @@ normal:
     name: 'Project SEKAI: Colorful Stage!'
     weight: 2
     state: Rhythm Game
+  - type: watching
+    name: YouTube
+    weight: 2
+    state: Music Videos
+  - type: competing
+    name: osu!
+    weight: 1
+    state: Ranked Match
   sleepy:
   - type: listening
     name: Yuki no Hahen
@@ -156,6 +177,14 @@ normal:
     name: 'The Legend of Zelda: Tears of the Kingdom'
     weight: 2
     state: Adventure
+  - type: watching
+    name: VOCALOID tutorials
+    weight: 1
+    state: on YouTube
+  - type: watching
+    name: science documentaries
+    weight: 1
+    state: Discovery Channel
   shy:
   - type: listening
     name: Koi wo Sensou
@@ -210,6 +239,10 @@ normal:
     name: Civilization VI
     weight: 2
     state: 4X Strategy
+  - type: watching
+    name: chess tournament
+    weight: 1
+    state: PGN Livestream
   melancholy:
   - type: listening
     name: Kokoro
@@ -260,6 +293,10 @@ normal:
     name: 'Project SEKAI: Colorful Stage!'
     weight: 2
     state: Rhythm Game
+  - type: streaming
+    name: karaoke stream
+    weight: 1
+    url: https://www.youtube.com/watch?v=CGbYfNq3iZQ
   romantic:
   - type: listening
     name: Romeo and Cinderella
@@ -306,6 +343,10 @@ normal:
     name: Elden Ring
     weight: 2
     state: Action RPG
+  - type: watching
+    name: rage compilations
+    weight: 1
+    state: YouTube
   angry:
   - type: listening
     name: Two-Faced Lovers
@@ -331,6 +372,14 @@ normal:
     name: Hades
     weight: 2
     state: Roguelike
+  - type: competing
+    name: Valorant
+    weight: 1
+    state: Ranked
+  - type: streaming
+    name: speedrun attempts
+    weight: 1
+    url: https://www.youtube.com/watch?v=3J8EeHxg3po
   silly:
   - type: listening
     name: PoPiPo
@@ -364,6 +413,14 @@ normal:
     name: Fall Guys
     weight: 2
     state: Party Game
+  - type: competing
+    name: Fall Guys
+    weight: 2
+    state: Tournament Mode
+  - type: watching
+    name: funny fails compilation
+    weight: 1
+    state: YouTube
   test:
   - type: playing
     name: G
@@ -390,6 +447,10 @@ evil:
     name: Devil May Cry 5
     weight: 2
     state: Action
+  - type: competing
+    name: DOOM Eternal
+    weight: 2
+    state: Ultra Nightmare
   cunning:
   - type: listening
     name: Gekkabijin
@@ -503,6 +564,10 @@ evil:
     name: Neon White
     weight: 2
     state: FPS Platformer
+  - type: streaming
+    name: chaos speedrun
+    weight: 1
+    url: https://www.youtube.com/watch?v=3J8EeHxg3po
   jealous:
   - type: listening
     name: Rotten Girl Grotesque Romance
@@ -583,3 +648,7 @@ evil:
     name: Crusader Kings III
     weight: 2
     state: Grand Strategy
+  - type: watching
+    name: world domination tutorials
+    weight: 1
+    state: YouTube