v0.3.0 - CASE/WHEN, table output, COALESCE, follow mode, and 20+ new functions

Added

Output & Display

• Table output: --format table or -t renders results as aligned terminal tables with headers and separators
• YAML output: --format yaml renders results as YAML (uses pyyaml if available, built-in fallback otherwise)
• --explain mode: shows parsed query breakdown (fields, conditions, grouping) and the generated jq filter
• --time flag: prints parse/execute/format timing to stderr
• Auto-detect stdin: curl ... | jonq "select name" works without needing - as source

Query Language

• CASE/WHEN/THEN/ELSE/END: conditional expressions — select case when age > 30 then "senior" else "junior" end as level
• COALESCE: null fallback with nested function support — select coalesce(nickname, name) as display
• || operator: SQL-standard string concatenation — select first || ' ' || last as full_name
• IS NULL / IS NOT NULL: null checks in conditions — select * if email is not null
• Type casting: int(), float(), str() / string(), type()
• Date/time functions: todate(), fromdate(), date(), timestamp() with null-safe execution
• Utility functions: keys(), values(), trim(), ltrim(), rtrim(), tojson(), fromjson(), reverse(), sort(), unique(), flatten(), not_null(), to_entries(), from_entries()

Terminal UX

• Rich REPL: readline with persistent history (~/.jonq_history) and tab completion for field names + keywords
• --follow mode: stream NDJSON from stdin line-by-line — tail -f app.log | jonq --follow "select level, msg if level = 'error'"
• Shell completions: jonq --completions bash|zsh|fish generates completion scripts

Changed

• Version bump to 0.3.0
• Unified all function-name-to-jq-builtin mappings into a single _FUNC_MAP constant (eliminated 3 duplicate copies)
• Expression-only queries now properly map over array elements instead of wrapping the whole input
• Path-explorer schema preview now shows nested JSON paths like orders[].price instead of only shallow field listings
• Reuse bounded sync and async jq worker pools for repeated identical filters
• Main streaming execution path now chunks root-array JSON in memory instead of splitting to temp files
• Repositioned README/package metadata around JSON exploration and extraction

Fixed

• Null-sensitive functions (todate, tonumber) are now guarded against null input instead of crashing
• Schema validator recognizes CASE expressions, || operator, and coalesce — no longer rejects them as unknown fields
• Sync jq runtime errors that only write to stderr no longer hang waiting on stdout
• Async jq workers are cleaned up with their event loop, preventing leftover subprocess transport warnings
• --follow mode skips empty results instead of printing [] for non-matching lines