feat/user-facing profile view and edit pages - #52

Background

Users need a place to view their full profile and update it after the initial sign-up flow. The edit page reuses components from sign-up step 2 but as a flat form with current values pre-filled.

Changes

Backend

• No model/schema changes in this PR — pronouns and date_of_birth already exist on User from the prior structured-experience PR
• pronouns removed from the required-fields list in compute_missing_profile_fields() (app/core/profile_status.py) — no longer blocks profile completeness
• Reads continue to go through UserMeSlimResponse/UserMeFullResponse (GET /users/me/ and GET /users/me/?full=true); admin read is GET /admin/users/{user_id}/ via UserFullResponse — none of these changed in this PR
• GET /events/ (pre-existing route) is now actually consumed by the frontend for the competition-experience event picker

Frontend — /profile/[id] (profile view)

• Route guard redirects to /dashboard if currentUser.id !== profileId (string-coerced comparison on both sides)
• Fetches GET /users/me/?full=true on mount
• Displays: basic info (name, pronouns, email, phone, DOB, student/employer branch), competition experience, volunteer experience — both experience tables render as flat lists in API order; no grouping by event or sorting by year yet
• Floating "Edit profile" button links to /profile/[id]/edit
• Separate edit icon in ProfileHeader links to /account-settings, which doesn't exist yet — placeholder for a later PR
• Chapter membership tag and a locked/read-only indicator for NEXUS-sourced volunteer entries are planned for later PRs (chapter membership depends on alumni chapters work tracked in #42; locking depends on an is_locked-equivalent field that doesn't exist on UserVolunteerExperience yet)

Frontend — /profile/[id]/edit (edit profile)

• Pre-fills all fields from GET /users/me/?full=true on mount
• Basic info: name, pronouns, phone, is_student toggle with student (university/major/status) or non-student (employer) branch, shirt size, dietary restriction, date of birth
• Experience flags: "I have no competition / volunteer experience" is a Yes/No radio (not a checkbox) that sets has_*_experience=false via PATCH /users/me/; unset fields are simply omitted from the PATCH body (dropped by the request serializer) rather than explicitly set to null, so under exclude_unset they're left unchanged, not reset
• Competition experience: add/edit/delete entries, event picked via searchable dropdown sourced from GET /events/, fields are event, school, notes
• Volunteer experience: add/edit/delete entries — all entries are currently editable the same way; no locked/read-only distinction for NEXUS-sourced entries yet (see above)
• Basic info saved via PATCH /users/me/ (exclude_unset — only changed fields sent)
• Reuses existing Input, Select, Textarea, RadioOption components, plus new profile-specific field components (see below)

Also included — supporting frontend changes

• dashboard/layout.tsx deleted; AuthProvider moved up to the root layout, so non-dashboard routes like /profile/[id] can use auth context
• New components: AvatarCircle, ProfileFields, and section components EducationCareerSection/LogisticsSection
• UserAvatar rewritten to use AvatarCircle and adds a "Profile" menu item linking to /profile/[id]
• Sign-up page substantially rewritten (716 lines) to extract and share the experience-table UI with the profile edit page

Also included — unrelated fixes swept into this range

• Tailwind v4 theme tokens wired up; cascade-layer reset fix (styling infra); tailwind.config.ts removed
• nexus_test database now auto-creates on a fresh Postgres volume (local dev infra)
• Email-verification page now uses useAuth() instead of the removed authApi.me()
• Combobox bug fix: an option that's fully typed but not explicitly selected from the dropdown wasn't being recognized
• Backend/frontend test updates reflecting the nested event schema on experience responses

Testing

• Manually walked profile view for a user with a full profile (all sections populated) and an incomplete one (banners/missing-field states)
• Manually walked edit flow: pre-fill, basic info save, add/edit/delete on both experience tables, has-no-experience radio toggling correctly
• Verified route guard redirects when viewing another user's /profile/[id]
• Verified date_of_birth never appears in any response other than self-view (UserMeFullResponse only — not on the admin-facing UserFullResponse)
• Confirmed branch builds/runs in isolation

Notes

• date_of_birth is self-view only, never exposed to other users; a TD-facing view exposing only age-threshold booleans is deferred to a later issue
• No individual GET routes for experience sub-tables — always read through GET /users/me/?full=true
• Locked/read-only NEXUS-sourced volunteer entries and chapter membership tags are not implemented yet — flagged above as planned future work, not bugs
• The unrelated fixes/infra commits listed above landed in this same commit stretch and are included here rather than split into their own PR, per prior pattern on this rewrite