- Add filter, index_type, included_columns, and comment fields to IndexInfo
- PostgreSQL: query pg_am for index type, use indnkeyatts to split key/included columns, retrieve index comments via obj_description()
- SQL Server: add type_desc, filter_definition, included columns via is_included_column
- MySQL: add INDEX_TYPE from information_schema.STATISTICS
- Oracle: add INDEX_TYPE from ALL_INDEXES
- DDL generation: add USING (PostgreSQL), type prefix + INCLUDE + WHERE (SQL Server), COMMENT ON INDEX (PostgreSQL)
- Frontend: update types, state mapping, SQL generation, and i18n translations
- PostgreSQL: rewrite column query from information_schema to pg_attribute for accurate type info via format_type(atttypid, atttypmod); extract character_maximum_length from atttypmod for varchar/bpchar; fix execute_query with persistent(false) and empty result fallback
- SQL Server: reconstruct column types with precision (varchar(max), decimal(p,s), datetime2(p)); stop dividing nvarchar/nchar CHARACTER_MAXIMUM_LENGTH by 2
- MySQL: use COLUMN_TYPE instead of DATA_TYPE for full type definitions; add CHARACTER_MAXIMUM_LENGTH; fix ONLY_FULL_GROUP_BY with MIN(NON_UNIQUE)
- Oracle: add CHAR_LENGTH/DATA_LENGTH for column type precision; fix INDEX_OWNER join to prevent cartesian product
- SQLite: fix PRAGMA injection via double-quote escaping; detect primary key indexes via origin column
- Add rust_decimal feature to sqlx and tiberius for proper Decimal type handling
- Fix try_get_unchecked<String> causing NULL or garbled output for numeric types
- Add numeric_precision and numeric_scale to ColumnInfo for all database drivers
- Update frontend to display precision (e.g., numeric(20,6)) in column headers
- Fix typeColorClass to handle type names with precision suffix
Root cause: PostgreSQL binary protocol sends NUMERIC as PgNumeric binary format,
not UTF-8 text. try_get_unchecked<String> attempted to decode binary bytes as UTF-8,
causing decode failures (NULL) or garbage characters (乱码).
- Add comment field to ColumnInfo (MySQL COLUMN_COMMENT, PostgreSQL col_description)
- Show column comments in sidebar tree nodes
- Show column comments on hover in data grid header
- Default MySQL charset to utf8mb4 for proper CJK support
Closes#14