feat : add profile page

docs/adr/0003-personal-guild-profile.md

@@ -0,0 +1,42 @@
+# ADR 0003: Personal guild profile read model
+
+- Status: Accepted
+- Date: 2026-08-06
+
+## Context
+
+Signed-in members need one private page that combines their Discord identity with XP,
+level progress, voice time, and leaderboard standing. The Discord bot remains the
+authoritative writer for `user_levels` and `voice_time`, while the website has only a
+read-only connection to those tables. XP values use `numeric(40,0)`, which may exceed
+JavaScript's safe integer range.
+
+## Decision
+
+1. `/profile` identifies the current member from the server-side NextAuth session and
+   Discord provider account. Anonymous visitors receive a Discord login prompt that
+   returns them to `/profile`; profiles cannot be selected by URL parameter.
+2. Discord identity, XP, and voice data load independently. Session identity is the
+   fallback when Discord member metadata is unavailable, and unavailable activity
+   sources report section-level errors.
+3. The stored bot level remains authoritative. Next-level progress duplicates the
+   bot's documented XP formula and performs all XP arithmetic with `bigint` before
+   converting the bounded percentage to a number. Level 200 is the maximum and does
+   not display a progress bar.
+4. XP and voice ranks use the public leaderboards' shared competition ranking. XP
+   rank excludes level-0 members. Voice time and rank include only voice and Stage
+   channels that currently exist in the guild.
+5. Missing activity rows display zero activity and no rank. The website does not
+   create rows or write inferred values back to the bot database.
+6. One public leaderboard SSE subscription refreshes an open profile after either an
+   XP event or a voice-time event. Redis remains a notification path rather than the
+   source of truth.
+
+## Consequences
+
+- A signed-in member sees only the profile associated with their own Discord account.
+- Profile totals and public leaderboard values share ranking and voice-channel scope.
+- The bot formula is a cross-service contract. Formula or maximum-level changes must
+  update the bot integration document and website helper together.
+- Large cumulative XP values remain exact through database reads, calculations, and
+  formatting.

docs/glossary.md

@@ -63,3 +63,15 @@ tables, combined with current Discord channel metadata.
 
 A minimal Redis notification on `erika:sse:leaderboards` that tells an open XP or VC
 page to refresh its Server Component data after a bot transaction commits.
+
+## Guild profile
+
+The private `/profile` view for the currently authenticated Discord member. It joins
+Discord identity and roles with that member's level, XP, current-channel voice time,
+and leaderboard ranks without exposing a public member-profile URL.
+
+## Level progress
+
+The member's XP accumulated since reaching their stored level, measured against the
+bot's XP requirement for the next level. Level 200 is the maximum and has no next-level
+progress bar.

docs/integrations/leaderboard-bot.md

@@ -3,6 +3,28 @@
 The Discord bot owns all writes to `user_levels` and `voice_time`. The website only
 subscribes to notifications and then reads the committed database state.
 
+## Level formula contract
+
+The website's personal profile calculates next-level progress from the bot's stored
+level and cumulative XP. Both services must use this exact formula:
+
+```text
+required(0) = 500
+required(level) = required(level - 1) + 100 + (level * 25)
+total(0) = 0
+total(level) = total(level - 1) + required(level - 1)
+```
+
+`required(level)` is the XP needed to advance from that level to the next. `total(level)`
+is the cumulative XP needed to reach that level. Level 200 is the maximum; the XP
+requirement caps at the level-199 value and the profile does not show next-level
+progress at the cap.
+
+Store cumulative XP as an integer value and update `xp` and `level` in the same bot
+transaction. Changing the formula or maximum level requires a coordinated website
+update because the website intentionally does not infer the formula from database
+metadata.
+
 ## Redis channel
 
 Publish leaderboard notifications to exactly: