LINUS ROUND 1: Delete dead code (rust/c), generic Store[T], tests, slim main.go

- Removed rust-service/, c-runtime/, kafka stubs
- Generic Store[T] pattern with real tests
- Slimmed main.go from 324 to ~50 lines
- Added config, middleware, store, ledger, pdf tests
- Frontend SPA shell with router
- Binary: 15.5MB -> 12MB

rust-service/target/.rustc_info.json

@@ -1 +0,0 @@
-{"rustc_fingerprint":8170899571127002677,"outputs":{"12203715465990969353":{"success":true,"status":"","code":0,"stdout":"rustc 1.96.0 (ac68faa20 2026-05-25)\nbinary: rustc\ncommit-hash: ac68faa20c58cbccd01ee7208bf3b6e93a7d7f96\ncommit-date: 2026-05-25\nhost: aarch64-unknown-linux-gnu\nrelease: 1.96.0\nLLVM version: 22.1.2\n","stderr":""},"7971740275564407648":{"success":true,"status":"","code":0,"stdout":"___\nlib___.rlib\nlib___.so\nlib___.so\nlib___.a\nlib___.so\n/home/bernt/.rustup/toolchains/stable-aarch64-unknown-linux-gnu\noff\npacked\nunpacked\n___\ndebug_assertions\npanic=\"unwind\"\nproc_macro\ntarget_abi=\"\"\ntarget_arch=\"aarch64\"\ntarget_endian=\"little\"\ntarget_env=\"gnu\"\ntarget_family=\"unix\"\ntarget_feature=\"neon\"\ntarget_has_atomic=\"128\"\ntarget_has_atomic=\"16\"\ntarget_has_atomic=\"32\"\ntarget_has_atomic=\"64\"\ntarget_has_atomic=\"8\"\ntarget_has_atomic=\"ptr\"\ntarget_os=\"linux\"\ntarget_pointer_width=\"64\"\ntarget_vendor=\"unknown\"\nunix\n","stderr":""}},"successes":{}}