Merged in bugfix/unify_prompt_exhibit_header (pull request #952)

Bugfix/unify prompt exhibit header

* Remove dead prompt_exhibit_header overrides and legacy get_exhibit_pages

Investigation (AST call tree analysis) proved both were dead code:

1. get_exhibit_pages() in preprocessing_funcs.py had ZERO callers in the
   entire codebase. It was superseded by get_exhibit_pages_new() which is
   the only live path (called by preprocess.one_to_n_exhibit_chunking).

2. Client prompt_exhibit_header overrides (2-arg) in bcbs_promise and
   clover prompt_calls.py were dead for two independent reasons:
   a) Their only consumer (get_exhibit_pages) has zero callers
   b) The live consumer (get_exhibit_pages_new) calls with 3 args —
      if the resolver returned the client 2-arg function, Python would
      raise TypeError. The SaaS 3-arg version was always running.

Verification:
- Programmatic AST call tree (local_scripts/call_tree_analysis.py)
  confirms zero callers and signature mismatch
- Resolver test confirms all clients resolve to SaaS 3-arg implementation
- Full unit suite: 1077 passed, 0 failures
- E2E: BCBS P…
* Merged dev into bugfix/unify_prompt_exhibit_header

* Add dev dependencies for local code index

Add tree-sitter, lancedb, and tiktoken as dev dependencies for a local
codebase indexing system. The index provides hybrid search (symbol table,
call graph, semantic embeddings, BM25) for token-efficient code exploration.

The index lives in a gitignored .index/ folder — each developer builds
their own locally.


Approved-by: Katon Minhas

pyproject.toml

@@ -38,6 +38,10 @@ dev = [
     "isort>=5.13.2",
     "pytest>=8.3.3",
     "pytest-mock>=3.14.0",
+    "tree-sitter>=0.25.2",
+    "tree-sitter-python>=0.25.0",
+    "lancedb>=0.30.2",
+    "tiktoken>=0.12.0",
 ]
 test = [
     "pytest>=8.3.3",