Name the server OMARCHY_REPO_HOST, not OMARCHY_BUILD_HOST

Builds now happen wherever the operator likes, so naming the destination after
building described the old arrangement rather than the current one. What the
push and deploy commands reach is the machine that serves pkgs.omarchy.org and
holds the signing key: the repository host. It also runs the scheduled builds,
which is why the trigger in omarchy-pkgs release points at the same place.

Resolution moves into helpers/host-helpers.sh, which all three commands now
share instead of repeating: --host, then OMARCHY_REPO_HOST, then .repo-host.
OMARCHY_BUILD_HOST and .build-host keep working as fallbacks, so existing
environments and checkouts are unaffected.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

README.md

@@ -78,7 +78,8 @@ bin/repo sync                           # Sync to remote
 ### Building Heavy Packages Locally
 
 Large packages build faster on a local machine than on the server. Build them
-here, then hand the artifacts to the build host, which signs and publishes them:
+here, then hand the artifacts to the repository host, which signs and publishes
+them:
 
 ```bash
 bin/repo deploy --package nvidia-580xx-utils   # Build here, publish from the host
@@ -94,7 +95,7 @@ bin/repo push --package nvidia-580xx-utils     # Upload + publish on the host
 
 `push` uploads to the host's `build-output/`, verifies checksums, and runs
 `bin/upload-prebuilt` there. Do not publish from a local checkout instead: only
-the build host holds the complete repository and the signing key.
+the repository host holds the complete repository and the signing key.
 
 ## Commands
 
@@ -182,25 +183,25 @@ publish packages built on another machine.
 
 ```bash
 bin/repo deploy --package nvidia-580xx-utils   # Build locally, publish from the host
-bin/repo deploy --host root@example.com        # Point at a specific build host
+bin/repo deploy --host root@example.com        # Point at a specific repo host
 bin/repo deploy --dry-run                      # Show the plan, change nothing
 ```
 
-Runs `build` then `push` in one command. The build host is resolved before the
-build starts, so a missing `--host` fails immediately rather than after a long
+Runs `build` then `push` in one command. The repository host is resolved before
+the build starts, so a missing `--host` fails immediately rather than after a long
 compile.
 
-### Push to the Build Host
+### Push to the Repository Host
 
 ```bash
 bin/repo push                                  # Push everything in build-output
 bin/repo push --package nvidia-580xx-utils     # Push one package
 bin/repo push --mirror stable --arch aarch64   # Pick mirror and architecture
-bin/repo push --host root@example.com          # Override the build host
+bin/repo push --host root@example.com          # Override the repo host
 bin/repo push --dry-run                        # Show the plan, transfer nothing
 ```
 
-Uploads packages from `build-output/` to the build host and publishes them there
+Uploads packages from `build-output/` to the repository host and publishes them there
 with `bin/upload-prebuilt` (sign → promote → update → sync). Use it when a package
 is quicker to build on a local machine than on the server.
 
@@ -209,9 +210,14 @@ signing key lives there and nowhere else, and only the host holds the complete
 repository that a correct database and sync require. Local machines therefore
 need no secrets.
 
-The host comes from `--host`, `$OMARCHY_BUILD_HOST`, or `.build-host`, in that
-order. Note that `.build-host` also arms the automatic build trigger in
-`bin/omarchy-pkgs release`; pass `--host` or set `OMARCHY_BUILD_HOST` to keep the
+The host comes from `--host`, `$OMARCHY_REPO_HOST`, then `.repo-host`. One
+machine both serves pkgs.omarchy.org and runs the scheduled builds, so the
+setting is named for the repository rather than for building, which now happens
+wherever you like. `OMARCHY_BUILD_HOST` and `.build-host` are the previous names
+and still work.
+
+Note that `.repo-host` also arms the automatic build trigger in
+`bin/omarchy-pkgs release`; pass `--host` or set `OMARCHY_REPO_HOST` to keep the
 two separate.
 
 Split packages are selected by their own names, not their pkgbase — pushing
@@ -315,8 +321,9 @@ stable — promotion is always this explicit step.
 ### Build trigger
 
 After pushing, the command triggers the build host over ssh when
-`OMARCHY_BUILD_HOST` is set (env var, or a hostname in the git-ignored
-`.build-host` file). Without it, the 6-hourly auto-release timer picks up the
+`OMARCHY_REPO_HOST` is set (env var, or a hostname in the git-ignored
+`.repo-host` file; `OMARCHY_BUILD_HOST` and `.build-host` still work). Without
+it, the 6-hourly auto-release timer picks up the
 change on its own.
 
 ## Directory Structure