chore: remove pre-plugin scribe_session_context.sh dogfood hook

Superseded by the plugin's own SessionStart hook (plugin/hooks/). This root
scripts/ copy read the now-deleted project .mcp.json (dead scribe-dev /
devassistant host), so it could never fire. Single Scribe environment now,
reached only via the Scribe plugin MCP.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scripts/scribe_session_context.sh

@@ -1,38 +0,0 @@
-#!/usr/bin/env bash
-# Scribe SessionStart hook (dogfood / pre-plugin).
-#
-# Curls the running Scribe dev instance for the operator's always-on rules +
-# active-project context and emits it as SessionStart `additionalContext` — the
-# push channel that lets Scribe surface reflexively (plan #755, Phase 1).
-#
-# FAIL-OPEN by design: any missing tool, missing config, network error, or
-# unreachable instance results in injecting nothing and exiting 0. A session
-# must NEVER be blocked because Scribe is down. Reads URL+token from the
-# project's .mcp.json so no secret lives in this tracked script.
-#
-# Superseded in Phase 2 by the same hook bundled in the Scribe plugin, where
-# URL+token come from plugin userConfig instead of .mcp.json.
-set -uo pipefail
-
-MCP_JSON="${CLAUDE_PROJECT_DIR:-.}/.mcp.json"
-command -v jq   >/dev/null 2>&1 || exit 0
-command -v curl >/dev/null 2>&1 || exit 0
-[ -f "$MCP_JSON" ] || exit 0
-
-# scribe-dev is the locally-wired instance (prod id 2 / dev id 3 per binding).
-url=$(jq -r '.mcpServers["scribe-dev"].url // empty' "$MCP_JSON" 2>/dev/null) || exit 0
-auth=$(jq -r '.mcpServers["scribe-dev"].headers.Authorization // empty' "$MCP_JSON" 2>/dev/null) || exit 0
-token=${auth#Bearer }
-[ -n "$url" ] && [ -n "$token" ] || exit 0
-
-base=${url%/mcp}
-body=$(curl -fsS --max-time 8 \
-  -H "Authorization: Bearer ${token}" \
-  "${base}/api/plugin/context?project_id=3" 2>/dev/null) || exit 0
-
-text=$(printf '%s' "$body" | jq -r '.context // empty' 2>/dev/null) || exit 0
-[ -n "$text" ] || exit 0
-
-jq -n --arg c "$text" \
-  '{hookSpecificOutput: {hookEventName: "SessionStart", additionalContext: $c}}'
-exit 0