docs: rename scripts directory to usm-scripts across documentation

Update all documentation references from `scripts/` to `usm-scripts/` as the recommended
directory name for executable scripts. This change standardizes the naming convention
and marks the old `scripts/` directory as legacy while promoting `usm-scripts/` as
the new standard.

README.md

@@ -30,11 +30,11 @@
     "simpleBuildEnvironment"
   ],
   "execs": {
-    "install": "usp-exec/install",
-    "remove": "usp-exec/remove",
-    "build": "usp-exec/build",
-    "rebuild": "usp-exec/rebuild",
-    "test": "usp-exec/test"
+    "install": "usm-scripts/install",
+    "remove": "usm-scripts/remove",
+    "build": "usm-scripts/build",
+    "rebuild": "usm-scripts/rebuild",
+    "test": "usm-scripts/test"
   }
 }
 ```

SPECIFICATION.md

@@ -130,7 +130,7 @@ Each of these directories are created by USM at runtime for each package.
 
 ## Executable Scripts
 
-All executable scripts except for `remove` and `postInstall` are run from the source directory (see above). They may be anywhere in the source package, but are often placed in a folder at the root of the package called `scripts`.
+All executable scripts except for `remove` and `postInstall` are run from the source directory (see above). They may be anywhere in the source package, but are often placed in a folder at the root of the package called `usm-scripts` (recommended).
 
 - `build` is the only required exec script, it has the needed commands to actually compile the program from source. The build directory is passed to this exec as the first argument.
 - `install` when specified will install the files into the install directory, in the same structure that it would if that directory were the filesystem root. The build directory is passed to this exec as the first argument, the install directory is passed as the second argument, and the install type ("fresh", "upgrade", "downgrade") is passed as the third argument.

slopdocs/structure.usm.manifest.executable-scripts.md

@@ -204,7 +204,7 @@ echo "All tests passed"
 ### Permissions
 All scripts must be executable:
 ```bash
-chmod +x scripts/build.sh
+chmod +x usm-scripts/build.sh
 ```
 
 ### Error Handling
@@ -257,8 +257,8 @@ USM sets these non-prefixed variables for all executable scripts:
 ## Script Locations
 
 Scripts can be placed anywhere in the package, but common conventions:
-- `scripts/`: Directory at package root
-- `usm-scripts/`: Directory at package root
+- `usm-scripts/`: Directory at package root (recommended)
+- `scripts/`: Directory at package root (legacy)
 - Package root: For simple packages
 
 ## Build System Integration

slopdocs/structure.usm.manifest.md

@@ -87,10 +87,10 @@ Executable scripts for different package lifecycle phases.
 
 ```json
 "execs": {
-  "build": "scripts/build.sh",
-  "install": "scripts/install.sh",
-  "acquire": "scripts/acquire.sh",
-  "test": "scripts/test.sh"
+  "build": "usm-scripts/build.sh",
+  "install": "usm-scripts/install.sh",
+  "acquire": "usm-scripts/acquire.sh",
+  "test": "usm-scripts/test.sh"
 }
 ```
 

slopdocs/structure.usm.manifest.packaging.md

@@ -7,7 +7,7 @@ USM (Universal Source Manifest) is a JSON-based package management system that d
 
 A USM package consists of:
 - `MANIFEST.usm`: JSON manifest file at the project root
-- `scripts/`: Directory containing executable scripts (optional)
+- `usm-scripts/`: Directory containing executable scripts (optional, recommended)
 - Source code and project files
 
 ## Creating a New Package