Flatten Ghost fingerprint packages

[nahiyankhan]

Category: improvement
User Impact: Ghost packages are easier to read and configure because manifest, facets, and checks now live directly in the package directory.
Problem: The old .ghost/fingerprint/ plus optional config.yml layout split package identity, generation facets, local routing, and host-wrapper location overrides across too many concepts. That made exact package targeting and stack discovery harder to explain and easier to misuse.
Solution: Flatten packages to .ghost/{manifest,intent,inventory,composition,validate}.yml, remove config.yml and memory-dir behavior, keep exact --package <dir> for direct targets, and use GHOST_PACKAGE_DIR as the single env-only default for stack discovery and scoped packages.

Follow-up cleanup:

• Treat .ghost/config.yml as fully removed outside historical/changelog text and negative tests.
• Keep ghostDir semantics scoped to stack discovery package slots, while exact --package mode reports concrete package directories.
• Add exact package examples using product-surface/, not .ghost.
• Fix arbitrary YAML lint detection so normal YAML files are not guessed as validate.yml; schema-bearing Ghost YAML still routes to the right linter.

Validation:

• pnpm check: passed
• pnpm test: passed, 404 tests
• pnpm build: passed in pre-push hook
• node packages/ghost/dist/bin.js lint .ghost: passed, 0 issues
• node packages/ghost/dist/bin.js verify .ghost --root .: passed, 0 issues

Changeset: added major changeset for @anarchitecture/ghost.

Ghost Review:

• node packages/ghost/dist/bin.js check --base origin/main: passed, 0 findings
• node packages/ghost/dist/bin.js review --base origin/main --format json: passed

Screenshots/Demos: N/A