fix(install): handle bare-string MCP entry in shell-metachar warning

.apm/instructions/tests.instructions.md

@@ -83,8 +83,8 @@ URL string is the same code shape as a security-critical sanitizer check, and
 the analyzer cannot tell them apart. Treating every URL assertion uniformly
 through `urlparse` keeps CI green AND reinforces the security pattern that
 production code must follow (see
-`src/apm_cli/install/mcp_registry.py::_redact_url_credentials` and
-`src/apm_cli/install/mcp_registry.py::_is_local_or_metadata_host`).
+`src/apm_cli/install/mcp/registry.py::_redact_url_credentials` and
+`src/apm_cli/install/mcp/registry.py::_is_local_or_metadata_host`).
 
 ## Other rules
 

.github/instructions/tests.instructions.md

@@ -83,8 +83,8 @@ URL string is the same code shape as a security-critical sanitizer check, and
 the analyzer cannot tell them apart. Treating every URL assertion uniformly
 through `urlparse` keeps CI green AND reinforces the security pattern that
 production code must follow (see
-`src/apm_cli/install/mcp_registry.py::_redact_url_credentials` and
-`src/apm_cli/install/mcp_registry.py::_is_local_or_metadata_host`).
+`src/apm_cli/install/mcp/registry.py::_redact_url_credentials` and
+`src/apm_cli/install/mcp/registry.py::_is_local_or_metadata_host`).
 
 ## Other rules
 

CHANGELOG.md

@@ -21,6 +21,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Marketplace `url:` sources now require `https://github.com/` or `http://github.com/` URLs; GHES, GitLab, and other non-GitHub hosts are no longer resolved. (#951)
+- Grouped the seven `apm_cli/install/mcp_*.py` helper modules into an `apm_cli/install/mcp/` subpackage and stripped the redundant `mcp_` prefix from each filename, aligning with the unprefixed-noun naming convention used by the rest of `install/`. Pure refactor; behaviour and public API unchanged. (#951)
 - `apm marketplace init` and `apm init --marketplace` next-step hints now point at `apm pack` (was `apm marketplace build`). (#722)
 - **Manifest contract: invalid `target:` values now raise a parse error.** Previously, an unknown token (or a CSV string like `target: opencode,claude,copilot,agents` instead of the YAML list `target: [opencode, claude, copilot, agents]`) was silently ignored, leaving `apm install` and `apm compile` to exit 0 while deploying nothing. The shared parser used by `--target` now also validates `apm.yml`'s `target:`, so the same input resolves the same way at every entry point. **Migration:** three previously-silent inputs now fail loud -- (1) unknown tokens (`target: bogus` -> fix the typo), (2) empty values (`target: ""`, `target: []` -> remove the line if you meant auto-detect), (3) `all` mixed with other targets (`target: [all, claude]` -> use `all` alone). Omitting `target:` entirely still triggers auto-detection. (#820)
 - Rename `DownloadStrategyManager` to `DownloadDelegate` to better reflect Facade/Delegate pattern (#918)
@@ -37,6 +39,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Fixed `AttributeError: 'str' object has no attribute 'get'` crash when running `apm install --mcp <name>` without `--transport`, `--url`, `--mcp-version`, `--registry`, or a post-`--` stdio command. The bare-string registry shorthand now exits 0 and persists correctly to `apm.yml`. Closes #938 (#951)
 - `apm install` and `apm compile` no longer exit 0 with success messages when `target:` in `apm.yml` is a CSV string -- the value now parses identically to the same input on `--target`, and zero-target resolution surfaces a warning instead of a silent no-op. (#820)
 - Remove redundant `seen` set from `_scan_patterns()` discovery walk (#918)
 - `apm pack` (marketplace producer) now respects `GITHUB_HOST` for GitHub Enterprise repos -- ref resolution, token lookup, and metadata fetch all use the configured host instead of hardcoded `github.com`. `git ls-remote` is authenticated so private repos work without separate credential setup. (#1008)