Changes all sleep screen display refreshes and boot screens from
FULL_REFRESH to HALF_REFRESH to match OEM firmware behavior. The stock
firmware uses a single-pass 0xD7 waveform for sleep screens, not the
multi-flash GC waveform (0xF7) that FULL_REFRESH triggers. For grayscale
mode, HALF_REFRESH is required because the gray nudge LUT is calibrated
against the pixel charge state left by the single-pass waveform; using
FULL_REFRESH causes blotchy noise in gray areas. Also adds X3 wb_gc
passive byte (the one-byte 0x54 to 0x00, matching stock's passive WB
table in the gc nudge bank): Every X3 grayscale render, reader AA,
covers, and the sleep-cover nudge, gets it.
Display a Bluetooth icon in the status bar when BLE is connected. Also optimize memory management by lending the framebuffer instead of immediately tearing down BLE when heap is low, allowing BLE to remain active during rendering.
Temporarily release framebuffer memory during section pagination to reduce heap pressure. The framebuffer can be released before memory-intensive operations and restored afterward, allowing BLE stack startup threshold to be lowered from 80KB to 70KB. Implements RAII-style FrameBufferBuildLoan class to ensure proper cleanup and automatic restart on restoration failure.
Add missingInclude suppression to prevent false positives on fresh CI checkouts where include paths are unresolved. Add inline suppression for constVariableReference warning where cppcheck cannot detect mutations without full include path resolution.
Reduce BLE stack memory usage from ~68KB to ~52KB by disabling unused NimBLE roles (peripheral, broadcaster), limiting connections to 1, and reducing buffer counts for ACL, HCI events, and ATT entries. Remove unused cloud components (esp_insights, esp_rainmaker) that require unavailable server certificates. These changes prevent stack collision with the render shed, eliminating restart flaps on the reader device.
Replace per-page buffer free+realloc pattern with capacity tracking that only reallocates when needed size exceeds current capacity. This prevents heap fragmentation from non-coalescing holes that occurred when each page's freed block rarely fit the next page's allocation. After a few page turns, capacities converge on the book's maximum and page turns stop touching the allocator entirely.
Prevent OOM aborts by shedding BLE stack when free heap drops below 24KB before rendering. Lower BLE start threshold from 100KB to 80KB to match steady-state heap levels (~84KB). Reserve vector capacity upfront in page parsing to avoid reallocation crashes on fragmented heaps. Gate background section builds on heap availability.
Justin Mitchell