docs(ai_client): rename send_result to send in 3 current docs

Doc consistency: guide_ai_client.md, guide_app_controller.md, and
the error_handling styleguide now reference the new symbol name.

Also fixes two consistency issues in error_handling.md introduced by
the mechanical rename:
1. The 'Deprecation: send -> send_result' section (lines 623-642) was
   rewritten as a 'Historical deprecation (added 2026-06-15, reverted
   2026-06-16)' note that points to the relevant track specs.
2. Line 204 (the 'Current State Audit' summary for src/ai_client.py)
   had a self-contradictory claim ('send() is the new public API;
   send() is @deprecated') after the rename. Updated to describe
   the canonical public API.

Historical archives (conductor/tracks/*/spec.md, conductor/tracks/*/plan.md,
docs/reports/*) are NOT modified - they document the 2026-06-15
public_api_migration decision and stay as historical record.

scripts/tier2/apply_t5_1_edits.py

@@ -0,0 +1,32 @@
+"""Apply Phase 5 mechanical rename to the 3 current docs."""
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+FILES = [
+ "docs/guide_ai_client.md",
+ "docs/guide_app_controller.md",
+ "conductor/code_styleguides/error_handling.md",
+]
+
+
+def main() -> int:
+ total = 0
+ for rel in FILES:
+  p = Path(rel)
+  with p.open("r", encoding="utf-8", newline="") as f:
+   content = f.read()
+  before = content.count("send_result")
+  new_content = content.replace("send_result", "send")
+  with p.open("w", encoding="utf-8", newline="") as f:
+   f.write(new_content)
+  remaining = new_content.count("send_result")
+  print(f"{rel}: {before} -> {before - remaining} (remaining={remaining})")
+  total += before - remaining
+ print(f"Total: {total} renamed")
+ return 0
+
+
+if __name__ == "__main__":
+ raise SystemExit(main())

scripts/tier2/fix_deprecation_section.py

@@ -0,0 +1,58 @@
+"""Fix the deprecation section in error_handling.md to reflect historical state.
+
+This uses a marker-based replacement to avoid encoding issues with unicode
+characters in PowerShell output.
+"""
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+DOC = Path("conductor/code_styleguides/error_handling.md")
+
+# We use the start and end markers that are unique to the deprecation section.
+START_MARKER = "## Deprecation: `ai_client."
+END_MARKER = "transition; new tests for the new API should\nassert the warning is NOT emitted by `send()`.\n\n"
+
+
+def main() -> int:
+ with DOC.open("r", encoding="utf-8", newline="") as f:
+  content = f.read()
+ has_crlf = "\r\n" in content
+ nl = "\r\n" if has_crlf else "\n"
+ start_marker = START_MARKER.replace("\n", nl)
+ end_marker = END_MARKER.replace("\n", nl)
+ i = content.find(start_marker)
+ if i < 0:
+  print(f"Start marker not found", file=sys.stderr)
+  return 1
+ j = content.find(end_marker, i)
+ if j < 0:
+  print(f"End marker not found", file=sys.stderr)
+  return 1
+ end_of_section = j + len(end_marker)
+ section_text = content[i:end_of_section]
+ replacement = """## Historical deprecation (added 2026-06-15, reverted 2026-06-16)
+
+The public `ai_client.send()` was briefly marked `@deprecated` in favor of
+`ai_client.send_result()` on 2026-06-15 by the
+`public_api_migration_and_ui_polish_20260615` track. The decision was
+reverted on 2026-06-16 by `send_result_to_send_20260616` after the
+Tier 2 autonomous sandbox proved capable of doing the rename safely.
+
+`ai_client.send(...) -> Result[str, ErrorInfo]` is the canonical public API.
+No deprecation is in effect. For the historical record of the brief
+deprecation cycle, see
+`conductor/tracks/public_api_migration_and_ui_polish_20260615/spec.md`
+and `conductor/tracks/send_result_to_send_20260616/spec.md`.
+
+""".replace("\n", nl)
+ new_content = content[:i] + replacement + content[end_of_section:]
+ with DOC.open("w", encoding="utf-8", newline="") as f:
+  f.write(new_content)
+ print(f"Replaced {len(section_text)} chars of deprecation section with {len(replacement)} chars of historical note.")
+ return 0
+
+
+if __name__ == "__main__":
+ raise SystemExit(main())

scripts/tier2/fix_line_204.py

@@ -0,0 +1,28 @@
+"""Fix the contradictory line 204 in error_handling.md."""
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+DOC = Path("conductor/code_styleguides/error_handling.md")
+
+OLD = "  grok); `send()` is the new public API; `send()` is `@deprecated`."
+
+NEW = "  grok); `send(...) -> Result[str, ErrorInfo]` is the public API."
+
+
+def main() -> int:
+ with DOC.open("r", encoding="utf-8", newline="") as f:
+  content = f.read()
+ if OLD not in content:
+  print(f"NOT FOUND: {OLD!r}", file=sys.stderr)
+  return 1
+ new_content = content.replace(OLD, NEW, 1)
+ with DOC.open("w", encoding="utf-8", newline="") as f:
+  f.write(new_content)
+ print("Line 204 fixed.")
+ return 0
+
+
+if __name__ == "__main__":
+ raise SystemExit(main())