feat: add bump-version.sh script for version management

Automates version bumps across all version source files:
- Cargo.toml (PRIMARY - workspace.package.version)
- debian/changelog (prepend new entry)
- debian/control (update Version field)
- scripts/build-package.sh (update VERSION variable)
- frontend/package.json (update version field)
- Stale references check after bump

Usage: ./scripts/bump-version.sh <new_version> <old_version>

crates/pm-core/Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "pm-core"
+version.workspace = true
+edition.workspace = true
+authors.workspace = true
+license.workspace = true
+
+[dependencies]
+tokio = { workspace = true }
+sqlx = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+toml = { workspace = true }
+thiserror = { workspace = true }
+anyhow = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true }
+uuid = { workspace = true }
+ulid = { workspace = true }
+chrono = { workspace = true }
+config = { workspace = true }
+axum = { workspace = true }
+sha2 = { workspace = true }
+hex = { workspace = true }
+aes-gcm = { workspace = true }
+rand = { workspace = true }