Ship always-on simulated cognitive accounting core (AtomSpace, PLN, ECAN, tensor k-means)

[Copilot]

Replace the broken/merge-conflicted cognitive scaffold with a correct, always-buildable simulated core so Chart-of-Accounts mirroring, ledger validation, attention, and clustering work without OpenCog or ggml.

Cognitive engine (libgnucash/engine)

• Rewrite gnc-cognitive-accounting as an in-process AtomSpace (handles, outgoing/incoming, SimpleTV, STI/LTI)
• Account/transaction mapping; PLN double-entry & n-entry TVs; trial-balance / P&L proof reports
• ECAN wage/rent/decay + Hebbian co-occurrence; MOSES heuristic strategies (JSON); URE point estimate + bounds
• Split messaging: GncCognitiveAtomMessage (accounting) vs GncCognitiveModuleMessage (comms hub); C receive via GArray*
• Scheme path is export-only (no untrusted eval of book data)

Lifecycle & build

• Init/shutdown from gnc_engine_init / gnc_engine_shutdown; auto QOF hooks behind GNC_COGNITIVE_AUTO=1
• Optional HAVE_GGML link/include on gnc-engine; config.h template updated

Tensor network

• Feature schema v1 (8-d); real k-means / Cogfluence clustering; control messages without payload for task/autonomy nodes

Tests & docs

• Align unit tests with TV semantics and commodity fixtures (test-cognitive-accounting, test-tensor-network)
• test-cognitive-accounting.sh runs ctest when a build tree exists
• Truth-up COGNITIVE_ACCOUNTING.md and IMPLEMENTATION_REPORT.md

gnc_cognitive_accounting_init();
GncAtomHandle a = gnc_account_to_atomspace(acct);
gdouble score = gnc_pln_validate_double_entry(tx);  /* ~strength×confidence */
/* auto hooks: GNC_COGNITIVE_AUTO=1 */

Out of scope here: Guile module / UI reports, real OpenCog backend adapter, large-book hardening.