Rename peo4c to peo

Renames the Python package, environment variables (PEO4C_* to PEO_*), the
SQL helper schema, image paths and the entrypoint script.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/smoke_test.py

@@ -1,10 +1,10 @@
 # SPDX-FileCopyrightText: 2026 Bart Broere
 # SPDX-License-Identifier: GPL-3.0-or-later
-"""End-to-end smoke test for a running peo4c bridge, using the official Neo4j driver.
+"""End-to-end smoke test for a running peo bridge, using the official Neo4j driver.
 
 Usage: python tests/smoke_test.py [bolt-uri] [user] [password]
 Requires: pip install neo4j
-Set PEO4C_SMOKE_PG_DSN (e.g. "host=localhost dbname=postgres") to also check the
+Set PEO_SMOKE_PG_DSN (e.g. "host=localhost dbname=postgres") to also check the
 generated property columns over SQL; that needs psycopg.
 """
 
@@ -18,7 +18,7 @@ from neo4j.graph import Node, Path, Relationship
 uri = sys.argv[1] if len(sys.argv) > 1 else "neo4j://localhost:7687"
 user = sys.argv[2] if len(sys.argv) > 2 else "postgres"
 password = sys.argv[3] if len(sys.argv) > 3 else "postgres"
-GRAPH = "peo4c_smoke"
+GRAPH = "peo_smoke"
 
 
 def check(label, condition):
@@ -121,7 +121,7 @@ MATCH ()-[]->() RETURN { name:'relationships', data: count(*)} AS result
 
         check("managed write transaction", s.execute_write(work) == 1)
 
-    dsn = os.environ.get("PEO4C_SMOKE_PG_DSN")
+    dsn = os.environ.get("PEO_SMOKE_PG_DSN")
     if dsn:
         import psycopg