Prepare v1.2.0-rc.1 qualitative battery UX

[vermi5]

What changed

• Replace public battery percentages with Critical, Low, Medium, High, and Top across the tray, tooltip, local API, diagnostics, and Rainmeter.
• Keep charging/charged as an independent state; Dock 0x06 is Top / Charging, while confirmed active-to-inactive 0x06 becomes Top / Charged.
• Harden Dock removal, sleep/off, wake, unavailable, and transient Critical handling without changing the existing active EF stability filter.
• Add the five-colour level palette, saturated controller LED colours, and source-aware red/yellow/blue Dock charging accents.
• Update the local API to schema version 4 and align the bundled Rainmeter skin.
• Set assembly metadata to 1.2.0.0 / 1.2.0-rc.1 and teach the tag workflow to publish suffixed versions as GitHub prereleases.

Why

Space Station uses five ordinary battery presentations plus a special charging glyph. Real Dock captures also show that raw state, charging activity, physical LED colour, controller presence, and completed charge are separate signals. The previous percentage-oriented presentation conflated those concepts and allowed short HID/Dock transitions to flash unavailable or Critical states.

Impact

The tray and Rainmeter now present source-independent qualitative levels. The local status API removes percent and estimated, so consumers must use schemaVersion: 4, bandLevel, band, charging, and power.

Validation

• VaderBatteryTray/build.cmd
• VaderBatteryTray/build_led_protocol_test.cmd
• VaderBatteryTray/VaderLedProtocolSelfTest.exe
• git diff --check
• Local package: VaderBatteryTray-1.2.0-rc.1.zip
• Local SHA-256: D7A9766A9862DE1CBB0211A27B8D572B77328D12C4627DA340329E352A32CA23
• Physical Dock testing covered powered-off dock/undock, asleep/off presentation, active 0x04 High/Charging, firmware yellow pulse, and suppression of transient 0x01 Critical.