docs: add v0.34.9 release notes

Author: FahrenheitResearch

docs/releases/v0.34.9.md

@@ -0,0 +1,69 @@
+# BowEcho v0.34.9
+
+This release reduces repeated map and frame-processing work, improves several
+live-overlay workflows, and adds text export for every displayed sounding.
+
+## Performance and responsiveness
+
+- Surface-observation polling now follows the visibility of the METAR and
+  mesonet sublayers. State membership is cached while reports are parsed,
+  hover lookup is geographically bounded, and map interaction temporarily
+  uses a lighter station-model budget while panning or zooming.
+- Warning fills, outlines, and labels now share one resolved geometry result
+  per pane. Stable warning renderability, PDS status, and watch subtype data
+  are cached and invalidated when the alert generation changes.
+- Loop playback schedules the actual next-frame deadline instead of repeatedly
+  repainting an unchanged frame during its dwell. Extra panes still wake at
+  their own earliest render deadline.
+- Product inventories are built only when a configured product hotkey is
+  pressed, removing unused per-frame allocation work.
+- CREF, Echo Tops, VIL, VIL Density, and hail-derived full-volume products now
+  reuse precomputed row and gate mappings. Regression coverage verifies that
+  the optimized products retain their previous output values.
+
+## Radar and map workflow
+
+- The Shift magnifier now reads native polar data for DVEL and for base
+  velocity with automatic dealiasing, including the currently selected
+  dealias engine, instead of showing the older rasterized velocity view.
+- **More products** remains available while an extra radar pane is selected.
+- The maximum storm-track display choices now extend to 70 tracks.
+- Imperial range-ring annotations now show miles without a duplicate kilometer
+  value.
+- The bottom status area no longer repeats selected-scan text already visible
+  in the top scan readout; transient action and error messages remain visible.
+- Still screenshots always copy to the clipboard. Saving an additional PNG to
+  disk is now optional and remains enabled by default for existing settings.
+
+## Live overlays and reference layers
+
+- SPC outlooks, fire-weather outlooks, WPC outlooks, and storm reports now
+  request and install data for the exact current day and layer selection.
+  Results from an older request can no longer replace a newer selection, and
+  Day 3 hazard choices display the canonical probability layer.
+- Configured placefiles perform one lightweight text preload while disabled so
+  their parsed titles can appear before they are enabled. Disabled placefiles
+  still avoid icon-sheet loading and continuous refresh work.
+- River gauges now have a persistent, display-only state filter. Cached gauge
+  data is retained so state changes take effect immediately.
+- The aircraft layer now includes an on-demand, newest-first browser over the
+  preceding six public MADIS hourly files. Selecting a previous profile opens
+  it in BowEcho's native sounding viewer.
+
+## Sounding export
+
+- Every displayed sounding has an **Export** menu in both SHARPpy and Classic
+  modes, including model points, box means, observation-adjusted profiles,
+  RAOBs, aircraft profiles, local data, imported RAW soundings, and accepted
+  manual corrections.
+- The exact displayed profile can be copied as conventional SPC/SHARPpy RAW
+  text or saved as UTF-8 SHARPpy RAW or CSV. A correction that fails explicit
+  QC leaves the original profile visible and exportable.
+- Exported filenames are generated from available station and valid-time
+  metadata with filesystem-safe fallback names.
+
+## Operational notes
+
+- Every official release asset is built from the `v0.34.9` tag by GitHub
+  Actions. Matching `.sha256` files are published beside the Windows, macOS,
+  and Linux downloads.