[fix](binlog) Keep allocated LSN map alive during group flush cleanup

[foxtail463]

Problem Summary:
Group memtable flush stores a raw RowsetWriterContext* in SharedMemtable only to remove the segment’s allocated LSNs during teardown. A queued group flush task can retain SharedMemtable after FlushToken has released its GroupRowsetWriter and context, causing the later cleanup to dereference a freed context and crash the BE under ASan.

Solution:
Make SharedMemtable own the specific resource required for cleanup—the shared allocated-LSN map—rather than borrow the enclosing writer context. Capture the map only when the group writer requires allocated LSNs and assert that the map exists under that invariant. Both insertion during memtable conversion and removal during SharedMemtable teardown now operate directly on the retained map, so delayed task destruction remains safe after writer-context teardown.

[hello-stephen]

Thank you for your contribution to Apache Doris.
Don't know what should be done next? See How to process your PR.

Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[foxtail463]

run buildall

[foxtail463]

==306468==ERROR: AddressSanitizer: heap-use-after-free
READ of size 8 at 0x7d7670846328 thread T3835 (mf_normal [work)

#2 doris::RowsetWriterContext::remove_segment_allocated_lsns(long)
at be/src/storage/rowset/rowset_writer_context.h:198
#3 doris::SharedMemtable::~SharedMemtable()
at be/src/load/memtable/memtable_flush_executor.cpp:124
#7 doris::PartOfGroupMemtableFlushTask::~PartOfGroupMemtableFlushTask()
at be/src/load/memtable/memtable_flush_executor.cpp:82
#13 doris::ThreadPool::dispatch_thread()
at be/src/util/threadpool.cpp:628

freed by thread T3835 here:

#3 std::__shared_ptrdoris::RowsetWriter::~__shared_ptr()
#4 doris::FlushToken::~FlushToken()
#8 doris::PartOfGroupMemtableFlushTask::run()
at be/src/load/memtable/memtable_flush_executor.cpp:100
#9 doris::ThreadPool::dispatch_thread()
at be/src/util/threadpool.cpp:621

SUMMARY: AddressSanitizer: heap-use-after-free
be/src/storage/rowset/rowset_writer_context.h:198
in doris::RowsetWriterContext::remove_segment_allocated_lsns(long)

[foxtail463]

run buildall

[hello-stephen]

TPC-H: Total hot run time: 16876 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpch-tools
Tpch sf100 test result on commit 8a91e01da83afcc8a00ba94893ff1df20708d94a, data reload: false

------ Round 1 ----------------------------------
============================================
q1	17597	3113	3111	3111
q2	2104	274	237	237
q3	10216	870	525	525
q4	4667	242	203	203
q5	7682	558	384	384
q6	137	115	96	96
q7	524	494	387	387
q8	9249	840	930	840
q9	3448	2352	2383	2352
q10	6508	846	738	738
q11	405	198	187	187
q12	633	261	201	201
q13	18130	1550	1152	1152
q14	162	151	137	137
q15	q16	431	397	378	378
q17	1388	913	866	866
q18	3063	2275	2258	2258
q19	1289	904	743	743
q20	385	282	200	200
q21	5649	1649	1865	1649
q22	330	263	232	232
Total cold run time: 93997 ms
Total hot run time: 16876 ms

----- Round 2, with runtime_filter_mode=off -----
============================================
q1	3488	3412	3413	3412
q2	511	390	366	366
q3	2274	2304	2252	2252
q4	1186	1164	914	914
q5	2191	2111	2106	2106
q6	171	125	88	88
q7	1014	932	888	888
q8	1614	1444	1438	1438
q9	3132	3105	3104	3104
q10	1846	1840	1630	1630
q11	367	277	255	255
q12	454	427	345	345
q13	1500	1523	1158	1158
q14	189	195	163	163
q15	q16	390	399	364	364
q17	3543	3360	3139	3139
q18	4786	4379	4756	4379
q19	841	920	858	858
q20	1003	995	840	840
q21	3926	3278	3205	3205
q22	413	345	324	324
Total cold run time: 34839 ms
Total hot run time: 31228 ms

[hello-stephen]

TPC-DS: Total hot run time: 82104 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpcds-tools
TPC-DS sf100 test result on commit 8a91e01da83afcc8a00ba94893ff1df20708d94a, data reload: false

query5	4267	412	327	327
query6	387	139	140	139
query7	4928	430	236	236
query8	291	121	120	120
query9	8675	2970	2985	2970
query10	407	234	188	188
query11	5396	1032	909	909
query12	125	73	74	73
query13	1213	454	317	317
query14	6123	2202	2095	2095
query14_1	1994	1977	1964	1964
query15	179	117	114	114
query16	920	369	368	368
query17	798	470	365	365
query18	2333	336	240	240
query19	167	143	111	111
query20	87	70	76	70
query21	205	102	92	92
query22	5462	5351	5195	5195
query23	6773	6242	5936	5936
query23_1	6189	6091	6178	6091
query24	7263	1109	778	778
query24_1	787	773	782	773
query25	444	304	263	263
query26	1239	242	133	133
query27	2787	443	244	244
query28	4670	1486	1490	1486
query29	950	451	363	363
query30	254	157	133	133
query31	825	404	332	332
query32	123	79	79	79
query33	489	224	185	185
query34	991	820	473	473
query35	397	401	335	335
query36	578	593	516	516
query37	119	77	74	74
query38	999	847	829	829
query39	514	495	484	484
query39_1	473	460	441	441
query40	209	93	82	82
query41	59	58	62	58
query42	75	74	74	74
query43	244	247	211	211
query44	1064	535	538	535
query45	108	107	98	98
query46	758	855	526	526
query47	782	768	720	720
query48	309	310	232	232
query49	523	234	192	192
query50	741	264	193	193
query51	8095	8048	7975	7975
query52	72	65	59	59
query53	193	198	157	157
query54	220	186	150	150
query55	71	60	58	58
query56	214	173	170	170
query57	790	664	677	664
query58	200	164	163	163
query59	1255	1243	1130	1130
query60	251	184	203	184
query61	118	112	135	112
query62	353	202	192	192
query63	173	140	137	137
query64	2696	686	628	628
query65	1586	1678	1557	1557
query66	1866	281	211	211
query67	9953	9813	9736	9736
query68	3014	1225	692	692
query69	373	219	206	206
query70	682	634	610	610
query71	249	174	161	161
query72	2409	1829	1592	1592
query73	654	592	347	347
query74	2019	1223	1131	1131
query75	1193	1116	961	961
query76	2396	745	507	507
query77	250	266	223	223
query78	3860	3770	3255	3255
query79	2305	831	551	551
query80	1591	329	287	287
query81	500	159	135	135
query82	629	125	97	97
query83	283	209	192	192
query84	299	110	94	94
query85	788	366	302	302
query86	399	178	179	178
query87	1008	986	889	889
query88	2771	2110	2099	2099
query89	282	196	178	178
query90	2043	132	129	129
query91	132	124	98	98
query92	82	61	70	61
query93	1390	1205	740	740
query94	636	250	196	196
query95	523	324	235	235
query96	849	576	262	262
query97	1071	1054	1037	1037
query98	142	137	134	134
query99	432	346	312	312
Total cold run time: 178484 ms
Total hot run time: 82104 ms

[hello-stephen]

ClickBench: Total hot run time: 14.78 s

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/clickbench-tools
ClickBench test result on commit 8a91e01da83afcc8a00ba94893ff1df20708d94a, data reload: false

query1	0.01	0.00	0.01
query2	0.08	0.04	0.04
query3	0.25	0.10	0.12
query4	1.60	0.10	0.09
query5	0.18	0.15	0.16
query6	1.25	0.70	0.71
query7	0.03	0.00	0.01
query8	0.04	0.02	0.03
query9	0.28	0.22	0.22
query10	0.37	0.37	0.36
query11	0.16	0.11	0.12
query12	0.16	0.12	0.12
query13	0.31	0.32	0.31
query14	0.46	0.46	0.45
query15	0.37	0.36	0.35
query16	0.23	0.22	0.23
query17	0.70	0.71	0.67
query18	0.20	0.16	0.17
query19	1.22	1.20	1.25
query20	0.01	0.01	0.01
query21	15.48	0.16	0.11
query22	5.07	0.04	0.04
query23	16.17	0.26	0.10
query24	2.98	0.30	0.26
query25	0.11	0.05	0.03
query26	0.71	0.16	0.11
query27	0.04	0.03	0.03
query28	3.62	0.57	0.25
query29	12.48	3.20	2.61
query30	0.26	0.11	0.13
query31	2.76	0.37	0.18
query32	3.50	0.32	0.23
query33	1.35	1.50	1.43
query34	15.35	2.23	1.79
query35	1.81	1.76	1.70
query36	0.47	0.31	0.30
query37	0.06	0.04	0.04
query38	0.04	0.02	0.02
query39	0.03	0.02	0.03
query40	0.11	0.07	0.08
query41	0.07	0.03	0.02
query42	0.03	0.03	0.02
query43	0.04	0.04	0.03
Total cold run time: 90.45 s
Total hot run time: 14.78 s

[hello-stephen]

BE Regression && UT Coverage Report

Increment line coverage 100% (0/0) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	76.17% (34659/45500)
Line Coverage	61.25% (391199/638734)
Region Coverage	57.42% (328628/572328)
Branch Coverage	58.19% (149914/257617)