feat(ui): add Scanner Connecting state matching Figma node 32:20

[ilmoniemi]

User Story

As a Pyrycode mobile user whose QR scan succeeded, I want a connecting-feedback state during the handshake, so I have explicit feedback that pairing is in flight rather than wondering if the tap registered.

Context

Figma node 32:20 (Scanner — Connecting state variant) doesn't exist in code today. The current fake-pair flow in ScannerScreen.kt transitions instantly to ChannelList with no intermediate state. When the real CameraX + relay handshake lands in Phase 4 there's a real connecting window, so pre-building the visual now decouples Figma-fidelity work from network integration. Phase 1.5 Figma-anchored catchup wave, sibling to #61 (Scanner Denied).

Acceptance Criteria

• New screen-level composable in app/src/main/java/de/pyryco/mobile/ui/onboarding/ renders the Connecting state from Figma node 32:20: indeterminate circular progress, headline copy, and the server address the user just paired with
• Headline copy "Connecting to your pyrycode server…" matches Figma node 32:20 and uses an M3 typography role (no hardcoded TextStyle)
• Server address renders below the headline in a monospace FontFamily using the typography role Figma binds (architect verifies via get_design_context)
• Screen exposes the server address as a parameter; no data fetching, no navigation, no side effects
• All colors bind to MaterialTheme.colorScheme.* — zero hardcoded color literals
• @Preview composables for light and dark variants visually match the Figma screenshot side-by-side

Technical Notes

Scope discipline:

• Single new file alongside ScannerScreen.kt and ScannerDeniedScreen.kt. Do NOT wire into MainActivity's NavHost in this ticket — real connecting transitions arrive with CameraX in Phase 4.
• Mirror ScannerScreen.kt (95 LOC) and ScannerDeniedScreen.kt (168 LOC) for Surface, systemBarsPadding, and PyrycodeMobileTheme preview wrapping conventions.

Rendering pointers:

• Compose's built-in CircularProgressIndicator (indeterminate variant) supplies the 270° open-arc ring natively. The Figma file's hand-built 3-cubic-Bézier path is a Figma-API workaround and does not need to be replicated in Compose.
• Use the M3 typography roles the Figma binds (verify via get_design_context, do not guess).

Size Estimate

S — single file, ~60–100 production LOC: M3 layout (Surface + Column + indicator + two text lines) wrapped in light/dark previews. No Canvas illustration, no data layer, no navigation, no DI changes.

Figma

https://www.figma.com/design/g2HIq2UyPhslEoHRokQmHG?node-id=32-20

[ilmoniemi]

🤖 Product Owner — creates structured issues

po agent has completed work on this ticket (rework pass).

Agent output (click to expand)

Rework reasons (no downstream rework comment; refined against the #61 PO precedent):

- **Size:** `XS` → `size:s`. Body itself estimated 40–60 LOC; XS ceiling is <30 LOC. Same correction the #61 PO pass applied to "XS-S".
- **AC #1 de-prescribed:** dropped the explicit composable signature (`ScannerConnectingScreen(serverAddress: String)`) and the architect-level Compose-vs-Figma-API parenthetical. Behaviour described instead of code structure, per PO constraints. Compose rendering note relocated to Technical Notes.
- **AC #3 de-prescribed:** dropped the "M3 labelMedium" guess; architect picks the role from `get_design_context`. Monospace requirement preserved (behaviour, not role).
- **AC #6 dropped:** "NavHost wiring NOT required — pure visual ticket" is a meta-note, not testable. Moved to Technical Notes → Scope discipline, matching the #61 split.
- **Boundary tightened:** added explicit no-data-fetch / no-navigation / no-side-effects AC, mirroring #61's lambda-only contract pattern.
- **Theming guardrail added:** `colorScheme.*` binding AC, matching #57/#61.
- **Context anchored:** linked `ScannerScreen.kt` (95 LOC) and the just-merged `ScannerDeniedScreen.kt` (168 LOC) as convention mirrors; called out #61 as the sibling pattern.
- **Figma section preserved verbatim.**
- **Not security-sensitive** (visual UI; no auth/token/header/crypto/network-input).

Dispatcher auto-adds `ready:po` on completion.

Ready for human review. Move to the next column when approved.

[ilmoniemi]

🤖 Product Owner — creates structured issues

po agent has completed work on this ticket.

Agent output (click to expand)

Refined #62 and posted the rework summary.

Key changes:
- **Size**: `XS` → `size:s` label (body's own 40–60 LOC estimate exceeds the <30 LOC XS ceiling — same correction #61's PO pass made).
- **AC de-prescribed**: dropped the explicit `ScannerConnectingScreen(serverAddress: String)` signature, the Compose-vs-Figma-API architecture aside, and the "M3 labelMedium" role guess. Behaviour described instead of code structure.
- **Non-testable AC moved**: "NavHost wiring NOT required" → Technical Notes → Scope discipline, mirroring #61's split.
- **Boundary tightened**: explicit no-data / no-navigation / no-side-effects AC + `colorScheme.*` binding AC.
- **Context anchored**: `ScannerScreen.kt` (95 LOC) + `ScannerDeniedScreen.kt` (168 LOC) as convention mirrors.
- Not security-sensitive (no auth/token/header/crypto/network-input). Dispatcher auto-adds `ready:po`.

Ready for human review. Move to the next column when approved.

[ilmoniemi]

🤖 System Architect — defines Go interfaces, data flows, concurrency patterns

architect agent has completed work on this ticket.

Agent output (click to expand)

Spec committed. Summary:

- **Size:** S, no split needed (single new file `ScannerConnectingScreen.kt`, ~60-100 LOC, mirrors `ScannerDeniedScreen.kt`).
- **File overlap check:** clear — only `feature/60` is in flight; it touches `ScannerScreen.kt` (not the new file path).
- **Design source:** Figma node 32:20 fetched via `get_design_context` + `get_screenshot`. Dark surface with a 48dp M3 indeterminate `CircularProgressIndicator`, `bodyLarge` headline on `onSurface`, monospace server-address line on `onSurfaceVariant` via `bodyMedium` + `FontFamily.Monospace` override.
- **Key call-outs in the spec:** use M3 `CircularProgressIndicator` defaults (don't hand-roll the Figma 3-cubic-Bézier export), apply monospace via `Text(fontFamily = …)` rather than `style.copy(…)` to preserve the named-role binding, omit the Figma TopAppBar (precedent from #61, AC forbids navigation), light + dark `@Preview` pair with the same `"home.lan:7117"` literal Figma uses.

Ready for human review. Move to the next column when approved.