Add start_line/max_lines optional parameters to read_file for
line-range reading. Large files now return at most 200 lines (~16KB)
by default, with continuation hints to read the rest.
- start_line/max_lines: optional, 1-based, default 1/200, max 500
- Small files (≤200 lines, ≤16KB) returned unchanged when no range
- UTF-8-safe byte truncation at 16KB for dense content
- Returns total_lines, shown_lines, truncated, next_start_line
- Continuation hint using read_file itself (no new tools)
Schema backward compatible; large-file default behavior intentionally
bounded to prevent context bloat.
Zhiping
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