ref(billing): Update plan features copy and remove Developer plan changes link

[souredoutlook]

Update billing-related copy in two places in the AM checkout/cancel flows.

• Renames the label displayed in plan features from 'metric alerts' to 'Metric Monitors' to match updated product terminology.
• Displays '1,000' instead of 'Unlimited' for the metric detector limit on plans with an unlimited reserved value.
• Removes the link to the Zendesk article about upcoming Developer plan changes from the cancel subscription banner, as it is no longer relevant.

[github-actions]

📊 Type Coverage Diff

Metric	Before	After	Delta
Coverage	93.06%	93.40%	🟢 +0.34%
Typed	137,246	134,900	🔴 -2346
Untyped	10,238	9,528	🟢 -710

🔍 331 new type safety issues introduced

any-typed symbols (129 new)

File	Line	Detail
static/app/components/commandPalette/ui/cmdk.tsx	54	CMDKCollection (var)
static/app/components/core/button/linkButton.tsx	125	_o (var(binding))
static/app/components/core/slot/slot.tsx	14	EMPTY_STATE (var)
static/app/components/core/slot/slot.tsx	15	NOOP_DISPATCH (var)
static/app/components/events/autofix/v3/autofixEvidence.tsx	119	question (var(binding))
static/app/components/events/autofix/v3/autofixEvidence.tsx	120	dataset (var(binding))
static/app/components/events/autofix/v3/autofixEvidence.tsx	165	trace_id (var(binding))
static/app/components/events/autofix/v3/autofixEvidence.tsx	165	span_id (var(binding))
static/app/components/events/autofix/v3/autofixEvidence.tsx	200	event_id (var(binding))
static/app/components/events/autofix/v3/autofixEvidence.tsx	227	replay_id (var(binding))
static/app/components/events/autofix/v3/autofixEvidence.tsx	254	profile_id (var(binding))
static/app/components/events/autofix/v3/autofixEvidence.tsx	271	mode (var(binding))
static/app/components/events/autofix/v3/autofixEvidence.tsx	271	path (var(binding))
static/app/components/events/autofix/v3/autofixEvidence.tsx	278	code_url (var(binding))
static/app/components/events/autofix/v3/autofixEvidence.tsx	298	repo_name (var(binding))

...and 114 more

Non-null assertions (!) (136 new)

File	Line	Detail
static/app/components/assigneeSelectorDropdown.tsx	326	currentMemberList.find(member => member.id === assigneeId)!
static/app/components/charts/eventsChart.tsx	271	previousSeriesTransformer(prev)!
static/app/components/charts/eventsRequest.tsx	572	item[2]!
static/app/components/charts/utils.tsx	111	this.steps.at(-1)!
static/app/components/commandPalette/ui/commandPalette.tsx	891	nodeRootKey.get(a.key)!
static/app/components/commandPalette/ui/commandPalette.tsx	892	nodeRootKey.get(b.key)!
static/app/components/core/layout/styles.tsx	212	resolveMargin(margin as Margin, theme)!
static/app/components/core/layout/styles.tsx	270	value!
static/app/components/events/autofix/useExplorerAutofix.tsx	334	blocks[i]!
static/app/components/events/autofix/v3/pullRequestsCard.tsx	76	pullRequest.pr_url!
static/app/components/events/interfaces/frame/defaultTitle/index.tsx	225	(frame.mapUrl ?? frame.map)!
static/app/components/events/interfaces/threads/threadSelector/index.tsx	90	current!
static/app/components/events/interfaces/threads/threadSelector/lockReason.tsx	17	values[0]!
static/app/components/events/suspectCommits.tsx	57	project?.id!
static/app/components/events/suspectCommits.tsx	67	project?.id!

...and 121 more

Type assertions (as) (66 new)

File	Line	Detail
static/app/chartcuterie/timeseries.tsx	109	as string[] — theme.chart .getColorPalette(timeSeries.length - 1) ?.slice() as string[]
static/app/components/clippedBox.tsx	213	as HTMLElement — event.currentTarget as HTMLElement
static/app/components/commandPalette/ui/commandPalette.tsx	115	`as HTMLElement
static/app/components/commandPalette/ui/commandPalette.tsx	358	as React.ComponentProps<typeof StyledInputGroupInput> — mergeProps(mergedCollectionProps, { onChange: (e: React.ChangeEvent<HTMLInputEl…
static/app/components/core/drawer/index.tsx	188	as Element — e.target as Element
static/app/components/core/drawer/index.tsx	189	as Element — e.target as Element
static/app/components/feedback/useFeedbackCache.tsx	107	`as ListCache
static/app/components/pipeline/pipelineIntegrationVsts.tsx	85	as string — key as string
static/app/components/pipeline/testUtils.tsx	39	as Window — { closed: false, close: jest.fn(), focus: jest.fn(), } as unknown as Window
static/app/components/pipeline/testUtils.tsx	39	as unknown — { closed: false, close: jest.fn(), focus: jest.fn(), } as unknown
static/app/components/replays/table/replayBulkViewedActions.tsx	79	as string[] — selectedRows .map(replay => replay.project_id && String(replay.project_id)) .fi…
static/app/components/replays/table/replayTableHeader.tsx	48	`as string
static/app/data/platformKinds.ts	39	as PlatformKind — type as PlatformKind
static/app/data/platformKinds.ts	39	as PlatformKind — type as PlatformKind
static/app/stores/groupingStore.tsx	249	`as Array<{data: ApiFingerprint[]; links: string

...and 51 more

This is informational only and does not block the PR.