fix: remove duplicate docstrings from public functions in .c files

Public function docstrings belong exclusively in .h headers per
coding convention. Only static helper functions and static variables
retain docstrings in .c files. Removed 413 duplicate docstrings
across 185 files (15 CBM + 15 C SDK projects). All 30 projects
rebuild with zero errors.

drivers/0x0f_flash/0x0f_flash.c

@@ -70,14 +70,6 @@ static void _write_and_verify(void) {
     printf("Flash readback: %s\r\n", read_buf);
 }
 
-/**
- * @brief Application entry point for the on-chip flash demo
- *
- * Writes a demo string to the last flash sector, reads it back,
- * and prints the result over UART.
- *
- * @return int Does not return
- */
 int main(void) {
     stdio_init_all();
     _write_and_verify();

drivers/0x0f_flash/flash.c

@@ -33,17 +33,6 @@
 #include "hardware/sync.h"
 #include "pico/stdlib.h"
 
-/**
- * @brief Erase one 4096-byte sector and write data to on-chip flash
- *
- * The target address must be aligned to a 4096-byte sector boundary.
- * The function disables interrupts, erases the containing sector,
- * programs up to len bytes from data, and re-enables interrupts.
- *
- * @param flash_offset Byte offset from the start of flash (must be sector-aligned)
- * @param data         Pointer to the data buffer to write
- * @param len          Number of bytes to write (multiple of FLASH_DRIVER_PAGE_SIZE)
- */
 void flash_driver_write(uint32_t flash_offset, const uint8_t *data, uint32_t len) {
     uint32_t ints = save_and_disable_interrupts();
     flash_range_erase(flash_offset, FLASH_SECTOR_SIZE);
@@ -51,17 +40,6 @@ void flash_driver_write(uint32_t flash_offset, const uint8_t *data, uint32_t len
     restore_interrupts(ints);
 }
 
-/**
- * @brief Read bytes from on-chip flash via the XIP memory map
- *
- * Flash is memory-mapped starting at XIP_BASE (0x10000000). This function
- * copies len bytes beginning at flash_offset into out using the XIP read
- * path, which is always available without erasing.
- *
- * @param flash_offset Byte offset from the start of flash
- * @param out          Pointer to the destination buffer (must be len bytes)
- * @param len          Number of bytes to read
- */
 void flash_driver_read(uint32_t flash_offset, uint8_t *out, uint32_t len) {
     const uint8_t *flash_target_contents = (const uint8_t *)(XIP_BASE + flash_offset);
     memcpy(out, flash_target_contents, len);