[codex] Add live graph filtering controls

[TobiasRoeddiger]

Summary

• add per-channel live graph configuration sheets with visibility and filtering controls
• support low-pass, high-pass, combined band-pass, and notch display filtering for live graphs
• modularize chart chip, sheet, filter config, display cache, and IIR filter engine code
• bump OpenWearables to 1.4.0 and add release-history copy for graph filtering and power saving modes
• add spacing between stacked FOTA verification banners

Impact

Users can inspect live sensor streams more precisely from the graph UI while keeping channel visibility and filtering controls discoverable from the channel chips.

Validation

• dart format
• flutter analyze
• flutter test
• git diff --check
• Android debug build installed and launched on Pixel 9a

[github-actions]

Visit the preview URL for this PR (updated for commit 058149b):

https://open-earable-web--pr277-codex-live-graph-fil-lfxnuu3y.web.app

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[github-actions]

PR Build Artifacts

• Android APK: Download Android APK
• Linux Bundle: Download Linux Bundle
• Windows Runner: Download Windows Runner
• Web Bundle: Download Web Bundle

Full workflow run: https://github.com/OpenEarable/app/actions/runs/28586399302