feat(connector): core banking / LMS seam, one real adapter and four dialects

The loan book is the training label and the one input no public feed
supplies. Integrating with a lender's core is not a technical unknown —
it is an onboarding process per bank, with a schema agreed in a room.
What can be built before that room is the seam, and this is it.

CoreBankingConnector fetches and returns rows; it never writes. Mapped
rows go to LoanBookEntryService.stage — the same validator an uploaded
spreadsheet goes through, landing in the same manual_entry_batch with
the same preview. A parallel validator for the automated path would be
the obvious shape and would eventually enforce the no-PII rule
differently.

FileDropConnector is real: it reads the newest matching file from a
directory a bank delivers to, and leaves it there so a failed run is
repeatable. Finacle, FLEXCUBE, BaNCS and an in-house REST LMS are
simulated, each emitting the same portfolio in its own column dialect —
DPD_DAYS, OVERDUE_DAYS, DAYS_OVERDUE, daysPastDue — which is what makes
the case for a mapping layer rather than asserting it.

The mapping is {canonical: vendor}, keyed by canonical name, so an
unmapped vendor column has no route through and is dropped at the
boundary. CUST_NAME and MOBILE_NO stay out structurally rather than by
anyone remembering. Auto-commit is off on every profile: a sync stages
and stops, keeping the rule that nothing is written until someone has
seen what will be. simulated is stamped per run, not read from the
profile, so switching a profile live cannot make old runs look real.

Fixes a real defect this surfaced: FORBIDDEN_COLUMNS matched on the
exact normalised name, so CUST_NAME — what Finacle actually calls it —
was missed, and a directly uploaded bank file would have kept the
borrower's name in manual_entry_line.raw_row. Matching now splits
separators and camelCase, catching borrowerMobile too, while
loan_account_ref still splits clean.

Verified against a running instance: Finacle 44/44 accepted with 4
columns dropped, the file drop 2 accepted and 1 UNKNOWN_ENTERPRISE
rejected from a real CSV, and both CUST_NAME and borrowerMobile refused
at mapping save.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/main/java/com/lincfusion/udyamlinc/seed/UdyamDataSeeder.java

@@ -81,6 +81,7 @@ public class UdyamDataSeeder implements CommandLineRunner {
     private final UdyamUserRepository userRepository;
     private final PasswordEncoder passwordEncoder;
     private final InstitutionSeeder institutionSeeder;
+    private final com.lincfusion.udyamlinc.connector.ConnectorProfileSeeder connectorProfileSeeder;
 
     @Value("${udyam.seed.enabled:true}")
     private boolean seedEnabled;
@@ -114,6 +115,9 @@ public class UdyamDataSeeder implements CommandLineRunner {
         // The institutional tier last: it assigns the portfolio the steps above
         // created, so it has to see a finished book.
         institutionSeeder.seed();
+        // Connector profiles after the institutions they read from, since each
+        // names a partner bank by code.
+        connectorProfileSeeder.seed();
         log.info("UdyamLinc seed complete — {} enterprises on book", enterpriseRepository.count());
     }