feat(mobile): filter inbox reports by priority (port #2176)

[Gilbert09]

Ports the desktop filter inbox signal reports by priority feature (#2176) to the PostHog Code mobile app.

What changed

• Store (inboxFilterStore.ts): added priorityFilter: SignalReportPriority[] (empty = no filter), with togglePriority and setPriorityFilter actions. Persisted and cleared in resetFilters, matching the existing statusFilter / sourceProductFilter / suggestedReviewerFilter patterns.
• Param builder (utils.ts): added buildPriorityFilterParam, returning a deduped comma-separated string or undefined when empty (equivalent to desktop's helper, sibling to buildSuggestedReviewerFilterParam).
• Query wiring (useInboxReports.ts + api.ts + types.ts): the selected priorities flow into the reports query as a priority request param.
• UI (FilterSheet.tsx): added a Priority section with P0–P4 toggle rows and colored dots (P0 red, P1/P2 amber-orange, P3/P4 gray), reusing the existing OptionRow / SectionHeader primitives and theme colors.

Tests

• inboxFilterStore.test.ts: toggle on/off, accumulation, dedupe on setPriorityFilter, and clear-on-reset.
• utils.test.ts: buildPriorityFilterParam for empty (undefined), join, and dedupe.

Mobile inbox tests, biome lint, and typecheck all pass.

No desktop (apps/code) code was modified.

[greptile-apps]

Comments Outside Diff (1)

1. apps/mobile/src/features/inbox/utils.ts, line 178-238 (link)

   Priority filter omitted from analytics has_active_filters

   InboxViewedFilterState has no priorityFilter field, so buildInboxViewedProperties never sets has_active_filters: true when the user's only active filter is a priority selection. The call-site in inbox.tsx also doesn't pass priorityFilter (and couldn't — it's not in the interface). Every INBOX_VIEWED event fired while only a priority filter is active will report has_active_filters: false, silently under-counting filtered sessions in analytics.

   Prompt To Fix With AI

   This is a comment left during a code review.
   Path: apps/mobile/src/features/inbox/utils.ts
   Line: 178-238
   
   Comment:
   **Priority filter omitted from analytics `has_active_filters`**
   
   `InboxViewedFilterState` has no `priorityFilter` field, so `buildInboxViewedProperties` never sets `has_active_filters: true` when the user's only active filter is a priority selection. The call-site in `inbox.tsx` also doesn't pass `priorityFilter` (and couldn't — it's not in the interface). Every `INBOX_VIEWED` event fired while only a priority filter is active will report `has_active_filters: false`, silently under-counting filtered sessions in analytics.
   
   How can I resolve this? If you propose a fix, please make it concise.

Prompt To Fix All With AI

Fix the following 2 code review issues. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 2
apps/mobile/src/features/inbox/utils.ts:178-238
**Priority filter omitted from analytics `has_active_filters`**

`InboxViewedFilterState` has no `priorityFilter` field, so `buildInboxViewedProperties` never sets `has_active_filters: true` when the user's only active filter is a priority selection. The call-site in `inbox.tsx` also doesn't pass `priorityFilter` (and couldn't — it's not in the interface). Every `INBOX_VIEWED` event fired while only a priority filter is active will report `has_active_filters: false`, silently under-counting filtered sessions in analytics.

### Issue 2 of 2
apps/mobile/src/features/inbox/utils.test.ts:233-245
The three `buildPriorityFilterParam` cases are pure input/output pairs that fit naturally into `it.each`, consistent with how the sibling `toSuggestedReviewerWriteContent` and `reviewerMatchesAvailable` tests are written in the same file.

```suggestion
describe("buildPriorityFilterParam", () => {
  it.each([
    { name: "returns undefined for an empty selection", input: [], expected: undefined },
    { name: "joins selected priorities with commas", input: ["P0", "P2"] as const, expected: "P0,P2" },
    { name: "dedupes repeated priorities", input: ["P1", "P1", "P3"] as const, expected: "P1,P3" },
  ])("$name", ({ input, expected }) => {
    expect(buildPriorityFilterParam(input)).toBe(expected);
  });
});
```

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