fix(harnesses): stage tokens for agent UID, fix three broken auth paths

Mirrors agent-runtimes audit + fix. All three M22 Phase 9 wrapper-script
auth paths were broken since the cutover: each one ran as the agent UID
trying to `cat` a 0400 root-only ESO mount. Same root cause we hit on
minimax/z-ai earlier today.

Changes:

1. anthropic-cloud-paul-oauth/v1 (NEW in framework)
   - Mirrors agent-runtimes — was previously only present there.
   - init.sh stages oauth_token into ~/.claude/.credentials.json (Claude
     Code's native subscription-OAuth schema). No env, no apiKeyHelper,
     no wrapper. Restores the equivalent of what harness_init.py used to
     do for the legacy SOPS path.
   - The legacy `bin/anthropic-wrapper.sh` was dead code (never wired).

2. gitea-https/v1
   - init.sh stages the token to $HOME/.config/git/gitea-https-token
     (0600 agent:agent) and points the per-host git credential helper at
     the staged copy. Previously the helper `cat`d the ESO mount path
     and silently failed at every git invocation.

3. gitea-admin/v1
   - init.sh stages the token to $HOME/.config/gitea-admin/token
     (0600 agent:agent). Wrapper updated to read from the staged copy.
   - Removes stale `requires: anthropic-cloud/v1` (the only anthropic
     harness in agent-runtimes is anthropic-cloud-paul-oauth/v1).

Pattern matches gitea-ssh / minimax / z-ai: ESO mount stays root-only,
init.sh runs as root and `install -m 0600 -o agent -g agent`s a single
explicit copy. Per-secret enumeration; future ESO Secret keys remain
inaccessible by default.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

harnesses/contexts/gitea-admin/v1/init.sh

@@ -1,19 +1,60 @@
 #!/bin/bash
-# init.sh for gitea-admin harness (M22 Phase 9)
-# Sets up non-secret env vars and configures git credential helper.
-# Credential token is NOT exported here — only read at exec time by the wrapper.
+# gitea-admin init — stage the API token for the agent user and configure
+# the git credential helper.
+#
+# Threat model: keep the ESO mount root-only (mode 0400). init.sh runs as
+# root and `install`s a per-secret 0600 agent-owned copy at
+# $AGENT_HOME/.config/gitea-admin/token. The wrapper at
+# bin/gitea-admin-wrapper.sh reads the staged copy (not the ESO mount) at
+# exec time. Without staging, every wrapper invocation would fail at the
+# `cat` step because the wrapper runs under the agent UID and the ESO file
+# is root:root mode 0400.
+#
+# This was previously broken: the wrapper `cat`d the ESO mount path which
+# the agent could not read. Discovered during the M22 Phase 9 audit; the
+# wrapper-script approach was never re-validated post-cutover. Stage-and-
+# wrapper-points-at-stage matches gitea-ssh / gitea-https / minimax / z-ai.
+#
+# Rotation handling: per-container init. Long-running sessions need a
+# future scripts.control_loop hook to re-stage between operations.
 
 set -euo pipefail
 
-# Non-secret configuration
-export GITEA_BASE_URL="${GITEA_BASE_URL:-https://gitea.oreillyit.nz}"
+ESO_TOKEN="/run/agent/secrets/gitea-admin/token"
 
-# Ensure SSH directory exists with correct permissions
-mkdir -p /home/agent/.ssh
-chmod 700 /home/agent/.ssh
+if [ ! -r "$ESO_TOKEN" ]; then
+    echo "ERROR: $ESO_TOKEN not readable. Check ESO ExternalSecret acct-<gitea-admin-id>." >&2
+    exit 1
+fi
 
-# Configure git to use the gitea-admin credential helper wrapper
-# The wrapper reads the ESO-mounted token at exec time
-git config --global credential.helper "!/opt/harness/contexts/gitea-admin/v1/bin/gitea-admin-wrapper.sh git-credential-helper"
+AGENT_USER="${AGENT_USER:-agent}"
+AGENT_HOME=$(getent passwd "$AGENT_USER" | cut -d: -f6)
+if [ -z "$AGENT_HOME" ] || [ ! -d "$AGENT_HOME" ]; then
+    AGENT_HOME="/home/$AGENT_USER"
+fi
 
-echo "[gitea-admin] init complete"
+# Stage the token into a per-secret path owned by agent, mode 0600.
+# Wrapper reads from this path; ESO mount is never accessed at runtime by
+# the agent UID.
+STAGED_DIR="$AGENT_HOME/.config/gitea-admin"
+STAGED_TOKEN="$STAGED_DIR/token"
+mkdir -p "$STAGED_DIR"
+chown "$AGENT_USER:" "$STAGED_DIR" 2>/dev/null || true
+chmod 0700 "$STAGED_DIR"
+install -m 0600 -o "$AGENT_USER" -g "$AGENT_USER" "$ESO_TOKEN" "$STAGED_TOKEN"
+
+# Ensure SSH directory exists with correct permissions (legacy SSH path).
+mkdir -p "$AGENT_HOME/.ssh"
+chown "$AGENT_USER:" "$AGENT_HOME/.ssh" 2>/dev/null || true
+chmod 0700 "$AGENT_HOME/.ssh"
+
+# Non-secret configuration: GITEA_BASE_URL is set in harness env.
+
+# Configure git to use the gitea-admin credential helper wrapper. Run as
+# the agent user so ~/.gitconfig is owned correctly; otherwise root would
+# write into /root/.gitconfig and the agent's git wouldn't see the helper.
+WRAPPER_PATH="/opt/harness/contexts/gitea-admin/v1/bin/gitea-admin-wrapper.sh"
+su - "$AGENT_USER" -c "git config --global credential.helper '!$WRAPPER_PATH git-credential-helper'"
+
+echo "gitea-admin: token staged at $STAGED_TOKEN (0600 $AGENT_USER:$AGENT_USER)"
+echo "gitea-admin: git credential helper configured"