feat(economy): add /achievements milestone badges

15 one-time achievements over the lifetime stat counters (work/wealth/gambling/
crime/heists/fishing/streaks/prestige), each paying a modest one-time coin reward
when unlocked. Detection is lazy - opening /achievements claims any newly earned
(like quests roll on view) - so no per-command hook is needed, and rewards are a
bounded, one-time coin source.

- New achievements.py: ACHIEVEMENTS table, pure newly_earned/achievements_view,
  and locked do_check_achievements. New achievements_earned schema field.
- /achievements command (own view claims; viewing others is read-only) with
  progress bars, db_error handling, and an "unlocked" banner.

8 tests: threshold detection, one-time claim (no double pay), multi-unlock,
view progress capping.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013VbAVsrZuYesea99mPMmPT

commands/economy_profile_commands.py

@@ -10,6 +10,8 @@ from discord import app_commands
 from core import economy
 import strings as S
 
+from ._replies import reply_db_error
+
 
 def register_economy_profile_commands(
     tree: app_commands.CommandTree,
@@ -342,6 +344,53 @@ def register_economy_profile_commands(
         data = await economy.get_user(target.id)
         await interaction.response.send_message(embed=_balance_embed(target, data))
 
+    @tree.command(name="achievements", description=S.CMD["achievements"])
+    async def cmd_achievements(
+        interaction: discord.Interaction, kasutaja: discord.Member | None = None
+    ):
+        target = kasutaja or interaction.user
+        note = ""
+        # Only the invoker's own view claims newly-earned achievements.
+        if target.id == interaction.user.id:
+            res = await economy.do_check_achievements(interaction.user.id)
+            if not res["ok"]:
+                await reply_db_error(interaction)
+                return
+            if res["new"]:
+                names = ", ".join(
+                    f"{economy.ACHIEVEMENTS[a]['emoji']} {economy.ACHIEVEMENTS[a]['name']}"
+                    for a in res["new"]
+                )
+                note = S.ACHIEVEMENTS_UI["unlocked_note"].format(
+                    names=names, reward=coin(res["reward"])
+                ) + "\n\n"
+
+        data = await economy.get_user(target.id)
+        rows = economy.achievements_view(data)
+        earned_count = sum(1 for r in rows if r["earned"])
+        lines = [
+            S.ACHIEVEMENTS_UI["row_earned"].format(
+                emoji=r["emoji"], name=r["name"], reward=coin(r["reward"])
+            )
+            if r["earned"]
+            else S.ACHIEVEMENTS_UI["row_locked"].format(
+                emoji=r["emoji"], name=r["name"], progress=r["progress"],
+                goal=r["goal"], reward=coin(r["reward"]),
+            )
+            for r in rows
+        ]
+        title = S.ACHIEVEMENTS_UI["title"]
+        if target.id != interaction.user.id:
+            title += f"  ·  {target.display_name}"
+        embed = discord.Embed(
+            title=title,
+            description=note
+            + S.ACHIEVEMENTS_UI["desc"].format(earned=earned_count, total=len(rows))
+            + "\n\n" + "\n".join(lines),
+            color=0xF4C430,
+        )
+        await interaction.response.send_message(embed=embed)
+
     @tree.command(name="cooldowns", description=S.CMD["cooldowns"])
     async def cmd_cooldowns(interaction: discord.Interaction):
         data = await economy.get_user(interaction.user.id)