[DO NOT MERGE] SSM fin notify ,fin wait example test case

[anjana348]

Demonstrates the /dev/crashrpt driver. At startup it builds diagnostic data in memory (500 nodes × 48 bytes + 50 nodes × 64 bytes, each with a message up to 255 bytes). It spawns a high-priority "reporter" thread that registers with the kernel and parks in fin_wait(). When an assert fires, the kernel (at the top of up_assert()) wakes the reporter, which writes the diagnostics to a file (/tmp/crashrpt_r<N>.bin) before the board reboots. The file is written to a temp path and rename()'d only after flush+close, so readers never see a partial report.

Sub-commands (run from TASH shell):
| Command | Action |
| crashrpt_test init | Build the diagnostic data + start & register the reporter thread | | crashrpt_test status | Show what's registered and the max report size | | crashrpt_test crash | Raise ASSERT(0) to exercise the full capture path → reporter writes file → reboot |

Configs to enable:
| Config | Purpose | Default |
| CONFIG_CRASH_REPORT=y | Required — enables the kernel driver (os/drivers/crashrpt.c), the /dev/crashrpt device, and the up_assert() hook | n | | CONFIG_CRASH_REPORT_DEADLINE_MS=3000 | Max ms the asserter blocks waiting for the reporter | 3000 | | CONFIG_EXAMPLES_CRASHRPT_TEST=y | Builds this example app | n | | CONFIG_EXAMPLES_CRASHRPT_TEST_DIR="/tmp" | Directory where the report file is written | "/tmp" | | CONFIG_EXAMPLES_CRASHRPT_TEST_PRIORITY=254 | Reporter thread priority (must be high — SCHED_PRIORITY_MAX-1) | SCHED_PRIORITY_MAX-1 | | CONFIG_EXAMPLES_CRASHRPT_TEST_STACKSIZE=8192 | Reporter thread stack size | 8192 |

TASH>> crashrpt_test init # builds data, registers reporter
TASH>> crashrpt_test status # (optional) check state
TASH>> crashrpt_test crash # triggers ASSERT(0) → reporter writes /tmp/crashrpt_r0.bin → reboot