[beam] Fix navbar btn style

[crabinak]

@agritheory This should remove that styling issue on the navbar button. It will catch links within BeamBtn and override their styling. This style couldn't be scoped since the a link comes from outside the component, but should be unique enough since it uses the beam_btn class specifically.

[github-actions]

Coverage Report for ./beam

Status	Category	Percentage	Covered / Total
🔴	Lines	5.3% (🎯 70%)	7 / 132
🔴	Statements	5.59% (🎯 70%)	8 / 143
🔴	Functions	2.43% (🎯 70%)	1 / 41
🔴	Branches	0% (🎯 70%)	0 / 81

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Unchanged Files
beam/src/components/ActionFooter.vue	0%	100%	0%	0%	12-5
beam/src/components/BeamArrow.vue	0%	0%	100%	0%	2-4
beam/src/components/BeamDayDivider.vue	0%	0%	0%	0%	17-2
beam/src/components/BeamFilter.vue	0%	0%	0%	0%	18-9
beam/src/components/BeamFilterOption.vue	0%	0%	0%	0%	41-21
beam/src/components/BeamMetadata.vue	0%	0%	0%	0%	2-1
beam/src/components/BeamModal.vue	0%	0%	0%	0%	3-5
beam/src/components/BeamModalOutlet.vue	0%	100%	100%	0%	2
beam/src/components/BeamProgress.vue	0%	0%	0%	0%	22-3
beam/src/components/Confirm.vue	0%	0%	0%	0%	4-1
beam/src/components/ItemCheck.vue	0%	0%	0%	0%	9-3
beam/src/components/ItemCount.vue	0%	0%	0%	0%	20-1
beam/src/components/ListAnchor.vue	0%	100%	100%	0%	1
beam/src/components/ListItem.vue	0%	0%	0%	0%	27-15
beam/src/components/ListView.vue	0%	0%	0%	0%	29-2
beam/src/components/Navbar.vue	0%	0%	0%	0%	13-null
beam/src/components/ScanInput.vue	88.88%	100%	50%	87.5%	23
beam/src/components/SplitColumn.vue	0%	0%	100%	0%	5-8
beam/src/composables/mqtt.ts	0%	0%	0%	0%	8-40

Generated in workflow #471 for commit fff89fe by the Vitest Coverage Report Action