fix(package): keep every shipped module under the PuduLangMcp root #6

Behaviour

pudu.toml declares the module root PuduLangMcp, but 0.1.0 shipped App, Domain, Services, Utils, Constants, Errors, and Generated at the top level. Checking installs of 0.1.0, a consumer made by pudu init, with its own App/Context.pudu, failed to compile the package: E3035 Context declares no type Context in App/Completion.pudu.

• Every module now lives under src/PuduLangMcp/ as PuduLangMcp.*; only the executable entry src/Main.pudu sits beside the root.
• The suites moved under test/PuduLangMcp/, mirroring src.
• test/Package/LayoutTest refuses a shipped module that is outside the root or named differently from its path, and checks the manifest's root.
• tools/SyncDocs and tools/Mutate follow the new generated-corpus path.
• The wiki mirror moved to wiki/src/PuduLangMcp/ with a new root map. The grammar page gains the root-ownership law, and the README shows package use.
• The version is 0.1.1.

Verification (Pudu 0.1.1)

• pudu check, pudu fmt --check, and pudu lint are clean over src, test, and tools.
• pudu test test: 21/21 suites, 471 assertions.
• pudu build src/Main.pudu: 60 modules.
• The layout suite fails with a stray src/Stray.pudu (module Stray), naming the file.
• Every wiki link resolves. This also fixes a pre-existing link to a nonexistent App/Tools/Stdlib page.

Closes #5