v0.2.1: Definition language accuracy across the MCP surface

Definition language accuracy across the MCP surface

Fixed:

• water_dataframe_describe / water_dataframe_query named only water_get_series as a canvas producer — both now name water_find_sites, whose full match set has staged to a canvas since 0.1.12.
• row_count on water_dataframe_query counts rows returned, not rows matched; the description now says so and discloses that a match over 10,000 rows truncates silently. The sql input drops its series-only column list for a pointer to water_dataframe_describe.
• water_get_conditions no longer blames the gage for an empty stat table — NWIS publishes no daily-statistics percentile product at all for some parameters (commonly gage height, 00065). Its no-current-reading error now names the two-hour lookback and points at water_get_series.
• Server instructions: parameter 00065 is "Gage height".

Changed:

• Tool, resource, and server-instruction descriptions are single strings rather than concatenated fragments; the water_find_sites, water_get_readings, water_get_series, and water_get_conditions descriptions were also shortened.

Dependency bumps:

• @biomejs/biome ^2.5.0 → 2.5.4 (exact pin)

123 tests pass; bun run devcheck clean.

CHANGELOG v0.2.1