chat: add simplex_name to contact_profiles and group_profiles

Adds nullable simplex_name TEXT column and partial UNIQUE
(user_id, simplex_name) index to both contact_profiles and group_profiles
tables. Distinct from contacts.simplex_name / groups.simplex_name
(M20260603), which carry the user's locally-known label set by the
prepare-via-name path; the new columns will carry the peer's broadcast
claim received via XInfo / XGrpInfo (wired up in following commits).

src/Simplex/Chat/Store/Postgres/Migrations/chat_schema.sql

@@ -532,7 +532,8 @@ CREATE TABLE test_chat_schema.contact_profiles (
     preferences text,
     contact_link bytea,
     short_descr text,
-    chat_peer_type text
+    chat_peer_type text,
+    simplex_name text
 );
 
 
@@ -856,7 +857,8 @@ CREATE TABLE test_chat_schema.group_profiles (
     group_web_page text,
     group_domain text,
     domain_web_page bigint,
-    allow_embedding bigint
+    allow_embedding bigint,
+    simplex_name text
 );
 
 
@@ -2137,6 +2139,10 @@ CREATE INDEX idx_contact_profiles_contact_link ON test_chat_schema.contact_profi
 
 
 
+CREATE UNIQUE INDEX idx_contact_profiles_simplex_name ON test_chat_schema.contact_profiles USING btree (user_id, simplex_name) WHERE (simplex_name IS NOT NULL);
+
+
+
 CREATE INDEX idx_contact_profiles_user_id ON test_chat_schema.contact_profiles USING btree (user_id);
 
 
@@ -2321,6 +2327,10 @@ CREATE INDEX idx_group_members_user_id_local_display_name ON test_chat_schema.gr
 
 
 
+CREATE UNIQUE INDEX idx_group_profiles_simplex_name ON test_chat_schema.group_profiles USING btree (user_id, simplex_name) WHERE (simplex_name IS NOT NULL);
+
+
+
 CREATE INDEX idx_group_profiles_user_id ON test_chat_schema.group_profiles USING btree (user_id);