fix(backend): backtick-quote hyphenated catalog names in SQL queries

[kir445]

Problem

Databricks SQL requires identifiers containing hyphens to be backtick-quoted. When a Unity Catalog name contains hyphens (e.g., arc-dbx-uc-cdp), SQL queries like SHOW SCHEMAS IN arc-dbx-uc-cdp fail with parse errors because the engine interprets the hyphens as minus operators.

Solution

Two complementary fixes:

SQLWarehouse.py

• Added _quote_hyphenated_uc_identifiers() static method that automatically detects and backtick-quotes hyphenated identifiers in SQL
• It only modifies SQL outside string literals ('...', "...") and already-backticked identifiers, so existing queries are not broken
• Applied to all three execution entry points: query(), query_chunked(), and execute()

UnityCatalog.py

• Wrapped {catalog} with backticks in all 5 SQL f-strings:
  • SHOW SCHEMAS IN
  • SHOW TABLES IN
  • DESCRIBE
  • SELECT ... FROM information_schema.tables
  • SHOW VOLUMES IN

Example

-- Before (fails)
SHOW SCHEMAS IN arc-dbx-uc-cdp

-- After (works)
SHOW SCHEMAS IN `arc-dbx-uc-cdp`


Closes #124 

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