Fix pcb update behavior for kicad-style asset dependencies

[akhilles]

Ignore release candidates, and resolve MVS before materialization.

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Note

Medium Risk
Touches dependency resolution and update selection paths; incorrect version propagation could break KiCad asset aliasing or cause unexpected update behavior, but changes are scoped and covered by targeted tests.

Overview
Fixes KiCad asset handling so MVS-selected versions are consistently used during resolution: legacy [assets] entries are promoted into implicit [dependencies], sibling repo promotion anchors to an already-resolved sibling’s version, and asset materialization/resolution mapping now takes an explicit selected_kicad_assets set.

Updates pcb update version picking to ignore prerelease tags (e.g., -rc) when selecting both non-breaking and breaking candidates, and adds tests for the new asset-version and prerelease behaviors (plus changelog entries).

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 4 additional findings.

[github-actions]

Build Performance

Board	Base (median)	Head (median)	Change
demo/DM0001	117ms ±3	114ms ±4	-2.3%
demo/DM0002	100ms ±2	103ms ±1	+3.0%
demo/DM0003	113ms ±2	115ms ±2	+1.9%
arduino/Nano	78ms ±0.9	85ms ±3	1.10× ±0.03 slower
arduino/UNOQ	168ms ±8	168ms ±9	+0.2%

_{Measured with hyperfine. Times show median ±stddev.}

[devin-ai-integration]

Devin Review found 1 new potential issue.

View 5 additional findings in Devin Review.

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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