docs: add developer, testing and performance guides; record M0 resultsv0.1.0

- DEVELOPER_GUIDE: workflow, how the tooling works (verified simulator
  behaviour), conventions and how to add devices.
- TESTING and PERFORMANCE: test layers, M0 results and measured numbers.
- FEASIBILITY: what M0 verified (watchdog 120k/240k, 10 MB storage in
  device profiles, unreliable monkeydo exit code, icon sizes).
- README status, new make targets and layout; CHANGELOG 0.1.0.
- Author/Summary headers on every document, including the original brief.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/docs/FEASIBILITY.md b/docs/FEASIBILITY.md
index 255f195..cb3431a 100644
--- a/docs/FEASIBILITY.md
+++ b/docs/FEASIBILITY.md
@@ -1,3 +1,7 @@
+<!--
+  Author:  cirakg & claude ai
+  Summary: Phase 0 research: what the Connect IQ platform allows, with verdicts, decisions and sources.
+-->
 # Feasibility findings (Phase 0)
 
 Researched on 2026-10-18 against the Connect IQ SDK 9.2.0 documentation (API reference generated 2026-10-06), Garmin's device reference pages, and, where Garmin's documentation is silent, Garmin developer-forum reports. Forum-only evidence is marked **(forum)**. Nothing has been built yet. Anything marked **to measure** gets measured in the milestones, not estimated.
@@ -238,6 +242,18 @@ Rules that apply to every path (detailed in the README):
 - **Status**: one read-only status field summarises the last import.
 - **Editing and removing after import**: on the watch (delete, reorder, lock), or by re-importing.
 
+## Verified during M0 (2026-10-18)
+
+With SDK 9.2.0 and the device files of all 72 products installed:
+
+- **Headless simulator in Docker: confirmed.** Every library the simulator needs is in the Ubuntu 22.04 image; it runs under Xvfb, and unit tests, screenshots and diagnostics work on all four test devices.
+- **`monkeydo` exit code: confirmed unreliable.** It exits with 1 after a fully passing test run, so the test runner judges the console output.
+- **Unit-test summary format:** SDK 9.2.0 prints `PASSED (passed=1, failed=0, errors=0)`, not the `failures=` form in Garmin's documentation. The parser accepts both.
+- **Watchdog budget (11):** the device files give 120,000 bytecodes per event on the Forerunner 255 and 255S (the 512 KB watches) and 240,000 on every other target. Long work will be chunked for the smaller budget.
+- **Storage (4): new evidence.** Every target's simulator profile reports an app storage capacity of 10 MB, far above the "128 KB total" in Garmin's core-topic page. The design keeps the stricter figure until it's measured on your Forerunner 70 in M3.
+- **Launcher icons:** the 72 products use eight icon sizes (38 to 70 px). Each gets an exact-size icon, because the compiler warns when it scales one, and warnings fail the build.
+- **SDK login (11):** the CLI's browser login can't reach the container (it waits on a random localhost port), so `make sdk` uses email and password; that worked for your account.
+
 ## Decisions
 
 Answered on 2026-10-18: