[VERSION] Bump to v3.19.7

Updated version for release with 6 string method fixes:
- DEPYLER-0195: str.replace() type error fixed
- DEPYLER-0196: str.join() type error fixed
- DEPYLER-0197: str.find() return type fixed
- DEPYLER-0198: str.count() implemented
- DEPYLER-0199: str.isdigit() implemented
- DEPYLER-0200: str.isalpha() implemented

All 443/443 tests passing. Zero regressions.

Author: Claude

Cargo.toml

@@ -19,7 +19,7 @@ max_cyclomatic_complexity = 15
 required_documentation_coverage = 100.0
 
 [workspace.package]
-version = "3.19.6"
+version = "3.19.7"
 edition = "2021"
 authors = ["Depyler Contributors"]
 license = "MIT OR Apache-2.0"

crates/depyler-ruchy/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "depyler-ruchy"
-version = "3.19.6"
+version = "3.19.7"
 edition = "2021"
 authors = ["Depyler Contributors"]
 description = "Ruchy script format backend for Depyler Python-to-Rust transpiler"
@@ -32,7 +32,7 @@ rustpython-parser = { version = "0.4", features = ["full-lexer"] }
 rustpython-ast = { version = "0.4" }
 
 # Internal dependencies
-depyler-core = { path = "../depyler-core", version = "3.19.6" }
+depyler-core = { path = "../depyler-core", version = "3.19.7" }
 
 # Logging and diagnostics
 tracing = "0.1"