feat(profile): preserve encoder controller + Stream Deck + XL layout

[jack-arturo]

Summary

Phase 1 of Stream Deck + XL support. Fixes a data-loss bug in the profile writer and teaches it about the new 32-key / 6-dial / 1200×100 touchstrip hardware.

• Bug: profile_manager.write_page overwrote Controllers with a single Keypad entry, silently wiping Encoder (dial/touchstrip) bindings on every keypad update.
• Fix: Group incoming buttons by controller, edit only the targeted controller in place, leave all others untouched.
• New: controller: "keypad" | "encoder" | "dial" field on the button schema so a single streamdeck_write_page call can bind keys and dials in one go.
• Read side: streamdeck_read_page now returns buttons from every controller (each tagged with controller) and a per-controller layouts map; layout stays as the keypad layout for back-compat.
• Layouts: added 20GBX9901 → keypad 8×4 + encoder 6×1 to MODEL_LAYOUTS so empty pages validate against the real grid instead of the 5×3 fallback.

USB-direct path (server.py) is untouched — python-elgato-streamdeck 0.9.8 doesn't know Plus XL's USB PID yet, so that path can't enumerate the device. The profile-manifest writer is the right path for this hardware and doesn't depend on library support.

Test plan

• uv run pytest tests/ — 44 passed (5 new)
• uv run ruff check .
• uv run ruff format --check .
• Manual: write a keypad button via MCP on a real Plus XL profile and confirm existing dial bindings survive
• Manual: bind a dial via controller: "dial" and confirm it appears in the Elgato app after streamdeck_restart_app

Follow-ups (deferred)

• Phase 2: Iconify icon generator (streamdeck_create_icon_from_iconify)
• Phase 3: touchstrip image writes (1200×100 split across 6 zones)

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Implements multi-controller (Keypad + Encoder/Dial) support in the profile manifest reader/writer to support Stream Deck + XL, while fixing a controller data-loss bug when writing keypad updates.

Changes:

• Fixes write_page() to update only the targeted controller(s) instead of overwriting Controllers with a single Keypad entry.
• Extends read_page() to return buttons from all controllers and adds a per-controller layouts map (keeping layout as the keypad layout for compatibility).
• Adds a Plus XL model layout entry and introduces a controller field in the MCP button schema; adds tests covering multi-controller read/write behavior.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
profile_manager.py	Preserves and updates actions per controller; adds controller normalization/lookup helpers; adds model/controller-specific layouts.
profile_server.py	Extends MCP tool input schema to allow targeting keypad vs encoder/dial controllers.
tests/test_profile_manager.py	Adds Plus XL-shaped fixture and tests to validate multi-controller reads and preservation during writes.

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[jack-arturo]

@copilot apply changes based on the comments in this thread

[Copilot]

@copilot apply changes based on the comments in this thread

All three review comments addressed in commit 85e8cfb:

1. write_page() empty-buttons regression – when clear_existing=True and buttons=[], the code now defaults to targeting the Keypad controller so the existing behaviour (clearing a page with an empty list) is preserved. Added a regression test to lock this in.

2. controller schema – added "enum": ["keypad", "key", "button", "encoder", "dial"] and "default": "keypad" to the field definition so invalid values are rejected before they reach the runtime.

3. key description – updated to explicitly state row-major ordering (left-to-right, then top-to-bottom) for keypad controllers and a simple 0..N-1 index for encoder/dial controllers.