Rename GitTally to Werkator

`gitTally` is the name of another product in the git space, so the
rename is a precaution; nothing about what the build system does changes.

The name follows one rule: `Werkator` where it is prose, capitalized
where it is a Kotlin type and its file, lowercase everywhere a machine
reads it — the command, packages, paths, configuration keys and values,
the Gitea check context. Environment variables keep their convention and
are uppercase throughout.

Every configuration file is still found under its pre-rename name
(`ConfigFiles`): `.gittally.yml` at the repository root, in a build
worktree and as committed on a branch, `.git/gittally/.gittally.yml` for
the machine layer. The current name wins where both exist, and the old
file is then ignored rather than merged — two files side by side are a
half-done rename, not a layering. Without the fallback an installation
that updated without renaming would not fail: a configuration that is
not found leaves every setting at its default, so it would come up
looking healthy while having forgotten its credentials and its builds.

`docs/werkator-migrationsplan.md` lists what the fallback does not
cover and has to be moved by hand — above all the state directory
`.git/werkator/`, which holds the build history, the control token and
the worktrees, and has no fallback of its own.

`docs/migration-from-legacy.md` is deleted with this: it mapped the
legacy script's environment variables, and every host it addressed has
long since moved to the YAML configuration.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/examples/setup-werkator-selfhost.sh

@@ -0,0 +1,59 @@
+#!/usr/bin/env bash
+# Example: set up a Werkator instance that watches and builds Werkator itself.
+# Run from inside a working checkout of the Werkator repository.
+#
+# Usage:
+#   GIT_ACCOUNT=mi GIT_TOKEN=xxxx ./docs/examples/setup-werkator-selfhost.sh
+#   (both empty is fine for a public origin — commit statuses just won't be published)
+set -euo pipefail
+
+INSTALL_DIR="${INSTALL_DIR:-$HOME/werkator-selfhost}"
+GIT_ACCOUNT="${GIT_ACCOUNT:-}"   # technical Gitea user for HTTPS fetch + status API
+GIT_TOKEN="${GIT_TOKEN:-}"       # Gitea API token — stays in the uncommitted config file
+SERVER_PORT="${SERVER_PORT:-18080}"
+
+DEV_CHECKOUT=$(git rev-parse --show-toplevel)
+ORIGIN_URL="${ORIGIN_URL:-$(git -C "$DEV_CHECKOUT" remote get-url origin)}"
+
+# 1. Build the Werkator jar — the last Gradle run you ever start by hand.
+(cd "$DEV_CHECKOUT" && ./gradlew --console=plain build)
+
+# 2. Dedicated clone: builds run in worktrees under its .git/werkator/worktrees,
+#    completely separate from your dev checkout.
+mkdir -p "$INSTALL_DIR"
+cp "$DEV_CHECKOUT/build/libs/werkator.jar" "$INSTALL_DIR/werkator.jar"
+if [ ! -d "$INSTALL_DIR/repo/.git" ]; then
+    git clone "$ORIGIN_URL" "$INSTALL_DIR/repo"
+fi
+cd "$INSTALL_DIR/repo"
+
+# 3. Generate the config templates; existing files are kept. The clone already
+#    carries the committed .werkator.yml, so this only creates the machine config
+#    (.git/werkator/.werkator.yml).
+java -jar "$INSTALL_DIR/werkator.jar" init
+
+# 4. Machine-specific overrides and secrets (.git/werkator/ is never committed;
+#    this file deep-merges over .werkator.yml and wins).
+cat > .git/werkator/.werkator.yml <<EOF
+git:
+  account: "$GIT_ACCOUNT"
+  token: "$GIT_TOKEN"
+server:
+  port: $SERVER_PORT
+EOF
+chmod 600 .git/werkator/.werkator.yml
+
+# The committed .werkator.yml already builds Werkator itself:
+#   buildCommand: ./gradlew --console=plain --no-daemon test
+#   artifactDirs: [build/reports]
+
+# 5. Optional kick-start: put the local ref one commit behind origin so the very
+#    first poll triggers a build — otherwise Werkator waits for the next push.
+#    Builds never move this ref or touch this checkout, so lagging is harmless.
+git reset --hard --quiet HEAD~1 || true
+
+# 6. Run it (Ctrl-C stops it cleanly). For a permanent setup, run
+#    `java -jar "$INSTALL_DIR/werkator.jar" init --systemd` here instead and follow
+#    docs/deployment.md — the generated unit points at this jar and repo.
+echo "Werkator self-host: http://localhost:$SERVER_PORT/ — watching $ORIGIN_URL"
+exec java -jar "$INSTALL_DIR/werkator.jar" server