First version of the hit based CA tracker for ALICE3 IT/OT

[mpuccio]

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[mpuccio]

Please when/if you merge do not squash

[alibuild]

Error while checking build/O2/fullCI_slc9 for 92ededd at 2026-02-13 08:43:

## sw/BUILD/o2checkcode-latest/log
--
========== List of errors found ==========
++ GRERR=0
++ grep -v clang-diagnostic-error error-log.txt
++ grep ' error:'
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:82:41: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:84:42: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:86:39: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:88:41: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:90:52: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:92:48: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:94:48: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:96:49: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:98:48: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:102:43: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:104:39: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:106:47: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:108:58: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:110:57: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:112:54: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:114:58: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:116:44: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:118:57: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:120:59: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:124:44: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:126:58: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:128:48: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:130:51: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:132:49: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:134:60: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:136:52: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:138:48: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:140:53: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:142:50: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:144:53: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:146:53: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:148:53: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:150:54: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:152:45: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:154:51: error: statement should be inside braces [readability-braces-around-statements]
/sw/SOURCES/O2/15066-slc9_x86-64/0/Detectors/Upgrades/ALICE3/TRK/workflow/src/TrackerSpec.cxx:188:43: error: statement should be inside braces [readability-braces-around-statements]
++ [[ 0 == 0 ]]
++ exit 1
--

Full log here.

[mpuccio]

@fprino : the ITS part is minimal and discussed already with Felix, please have a look
@njacazio : can you have a look and merge if it is fine with you?

[njacazio]

Many thanks @mpuccio tagging also @fcolamar and @altsybee

[njacazio]

Indeed I squashed by mistake when merging. @mpuccio shall we revert and reopen?

[mpuccio]

@f3sch , can we live with this squashed? The changes in ITS are really minimal

[f3sch]

@njacazio reverting would create a much bigger mess, so no let's leave it like this. But in the future, we have to be careful if a PR touches production code.