184-Bug fix quest rewards to better incentivize harder quests

[RemainingDelta]

Changes

• Updated DEFAULT_QUESTS in quests.py with rebalanced token and XP rewards that better incentivize harder quests over easier ones
• Fixed init_default_quests in mongo.py to upsert by quest name on every startup instead of only inserting when the collection is empty, ensuring DB values always
  stay in sync with code

Before

Quest	Messages	Tokens	XP
Daily Chatter	80	50	200
Quick Convo	160	75	250
Engaged Today	240	100	300
Weekly Regular	500	250	1,000
Consistent Contributor	750	400	2,500
Server Pillar	1,000	600	3,000

After

Quest	Messages	Tokens	XP
Daily Chatter	80	50	100
Quick Convo	160	115	200
Engaged Today	240	250	300
Weekly Regular	500	225	1,000
Consistent Contributor	750	400	2,000
Server Pillar	1,000	640	3,000

Closes #184