feat: Claude Code context injection (UserPromptSubmit hook)

Closes the asymmetry the user surfaced: before this, Claude Code
captured every turn (Stop hook) but retrieval only happened when
Claude chose to call atocore_context (opt-in MCP tool). OpenClaw had
both sides covered after 7I; Claude Code did not.

Now symmetric. Every Claude Code prompt is auto-sent to
/context/build and the returned pack is prepended via
hookSpecificOutput.additionalContext — same as what OpenClaw's
before_agent_start hook now does.

- deploy/hooks/inject_context.py — UserPromptSubmit hook. Fail-open
  (always exit 0). Skips short/XML prompts. 5s timeout. Project
  inference mirrors capture_stop.py cwd→slug table. Kill switch:
  ATOCORE_CONTEXT_DISABLED=1.
- ~/.claude/settings.json registered the hook (local config, not
  committed; copy-paste snippet in docs/capture-surfaces.md).
- Removed /wiki/capture from topnav. Endpoint still exists but the
  page is now labeled "fallback only" with a warning banner. The
  sanctioned surfaces are Claude Code + OpenClaw; manual paste is
  explicitly not the design.
- docs/capture-surfaces.md — scope statement: two surfaces, nothing
  else. Anthropic API polling explicitly prohibited.

Tests: +8 for inject_context.py (exit 0 on all failure modes, kill
switch, short prompt filter, XML filter, bad stdin, mock-server
success shape, project inference from cwd). Updated 2 wiki tests
for the topnav change. 450 → 459.

Verified live with real AtoCore: injected 2979 chars of atocore
project context on a cwd-matched prompt.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/atocore/engineering/wiki.py

@@ -29,7 +29,6 @@ from atocore.projects.registry import load_project_registry
 _TOP_NAV_LINKS = [
     ("🏠 Home", "/wiki"),
     ("📡 Activity", "/wiki/activity"),
-    ("📥 Capture", "/wiki/capture"),
     ("🔀 Triage", "/admin/triage"),
     ("📊 Dashboard", "/admin/dashboard"),
 ]
@@ -337,16 +336,27 @@ def render_search(query: str) -> str:
 
 
 # ---------------------------------------------------------------------
-# Phase 7I follow-up — /wiki/capture: paste mobile/desktop chats
+# /wiki/capture — DEPRECATED emergency paste-in form.
+# Kept as an endpoint because POST /interactions is public anyway, but
+# REMOVED from the topnav so it's not promoted as the capture path.
+# The sanctioned surfaces are Claude Code (Stop + UserPromptSubmit
+# hooks) and OpenClaw (capture plugin with 7I context injection).
+# This form is explicitly a last-resort for when someone has to feed
+# in an external log and can't get the normal hooks to reach it.
 # ---------------------------------------------------------------------
 
 
 def render_capture() -> str:
-    lines = ['<h1>📥 Capture a conversation</h1>']
+    lines = ['<h1>📥 Manual capture (fallback only)</h1>']
     lines.append(
-        '<p>Paste a chat from Claude Desktop, Claude.ai (web or mobile), '
-        'or any other LLM. It goes through the same pipeline as auto-captured '
-        'interactions: extraction → 3-tier triage → active memory if it carries signal.</p>'
+        '<div class="triage-warning"><strong>This is not the capture path.</strong> '
+        'The sanctioned capture surfaces are Claude Code (Stop hook auto-captures every turn) '
+        'and OpenClaw (plugin auto-captures + injects AtoCore context on every agent turn). '
+        'This form exists only as a last resort for external logs you can\'t get into the normal pipeline.</div>'
+    )
+    lines.append(
+        '<p>If you\'re reaching for this page because you had a chat somewhere AtoCore didn\'t see, '
+        'fix the capture surface instead — don\'t paste. The deliberate scope is Claude Code + OpenClaw.</p>'
     )
     lines.append('<p class="meta">Your prompt + the assistant\'s response. Project is optional — '
                  'the extractor infers it from content.</p>')