[DB] Create share_links table with RLS policies

[Venkat-Kolasani]

What

Add a share_links table to Supabase with proper Row Level Security.

Schema

Column	Type	Notes
id	uuid	Primary key
user_id	uuid	FK to auth.users
token	uuid	Public-facing, generated server-side
snapshot	jsonb	Frozen or live config
snapshot_type	enum	'frozen' or 'live'
expires_at	timestamptz	Nullable
is_active	boolean	Default true
view_count	integer	Default 0
created_at	timestamptz	Default now()

RLS Rules

• Authenticated users can INSERT/UPDATE/DELETE only their own rows (user_id = auth.uid())
• Public (anon) can SELECT only by token column — never expose user_id in response

Acceptance Criteria

• Migration SQL file added under /supabase/migrations/
• RLS enabled and policies tested
• Anon select works by token, returns no user_id field

[Suji2007hub]

Assign me

[Venkat-Kolasani]

GSSoC contributors: Issues #19–#22 (share dashboard) are blocked until this database issue is done.

If you want to work on the sharing feature, comment here with your approach:

• SQL migration for share_links (see issue body)
• RLS policies (authenticated CRUD own rows; anon SELECT by token only, no user_id in response)
• Migration file location: docs/ (see existing *-migration.sql files)

I'll assign one contributor once the plan looks solid. See CONTRIBUTING.md.