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-ca/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "pm-ca"
+version.workspace = true
+edition.workspace = true
+authors.workspace = true
+license.workspace = true
+
+[dependencies]
+pm-core    = { path = "../pm-core" }
+tokio      = { workspace = true }
+serde      = { workspace = true }
+serde_json = { workspace = true }
+thiserror  = { workspace = true }
+anyhow     = { workspace = true }
+tracing    = { workspace = true }
+chrono     = { workspace = true }
+sqlx       = { workspace = true }
+uuid       = { workspace = true }
+rand       = { workspace = true }
+hex        = { workspace = true }
+sha2       = { workspace = true }
+rustls     = { workspace = true }
+rcgen      = { workspace = true }
+pem        = { workspace = true }
+time       = { workspace = true }