chore(tsconfig): drop baseUrl so the configs survive TypeScript 7

TypeScript 6 reports it as an error:

  Option 'baseUrl' is deprecated and will stop functioning in TypeScript 7.0.
  Specify compilerOption '"ignoreDeprecations": "6.0"' to silence this error.

The repo pins typescript 5.9.3, so the current typecheck is quiet, but an
editor running a newer TypeScript flags it, and it becomes a hard failure
whenever the pin moves to 7.

In both configs baseUrl only anchors `paths`, and `paths` has not needed
it since TypeScript 4.4 — entries resolve relative to the tsconfig that
declares them. Every path here is already written relatively
("./packages/…", "./src/*"), so removing the line is the whole change.

Chose this over `"ignoreDeprecations": "6.0"`: that key silences the
message for one major version and has to be revisited, while this makes
the configs correct.

Nothing relies on baseUrl for bare-specifier resolution — there are no
`from "packages/…"` or `from "src/…"` imports under packages/*/src or
tests/e2e.

Verified with the repo's own typescript:
  tsconfig.json       0 errors before, 0 after (234 files import via
                      @ccr/* or @/*, so a broken alias could not be silent)
  tsconfig.node.json  1 error before, 1 after, byte-identical output —
                      a pre-existing TS18003 (its include is
                      "build/**/*.mjs" and allowJs is off), untouched here.

Re-checked both under TypeScript 6.0.3: the deprecation is gone and no new
diagnostic replaces it.

tsconfig.json

@@ -15,7 +15,6 @@
     "noEmit": true,
     "noUnusedLocals": true,
     "noUnusedParameters": true,
-    "baseUrl": ".",
     "paths": {
       "@/*": ["./packages/ui/src/*"],
       "@ccr/cli/*": ["./packages/cli/src/*"],

tsconfig.node.json

@@ -5,7 +5,6 @@
     "moduleResolution": "NodeNext",
     "allowSyntheticDefaultImports": true,
     "esModuleInterop": true,
-    "baseUrl": ".",
     "paths": {
       "@/*": ["./src/*"]
     }