Update docs to reflect stages 1-4 complete and working email reply

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plan.md

@@ -29,21 +29,22 @@ For now, `allowed_sender` substring match is sufficient for exploration. Worth a
 
 ## Implementation Stages
 
-### Stage 1 — Explore the message object (current)
+### ✅ Stage 1 — Explore the message object
 Receive a message and `inspect()` the full imapflow msg object to understand what
 data is available (headers, body parts, envelope, flags, etc.).
 
-### Stage 2 — Prompt construction
-Parse the message into a well-formed prompt: sender, subject, body. Prefix with
-instructions telling Claude to reply via the CCC `send-email` action.
+### ✅ Stage 2 — Prompt construction
+Parse the message into a well-formed prompt using `mailparser`. Use HTML body for
+better encoding/structure fidelity. Instruct Claude to reply via CCC per
+`email_protocol.md`.
 
-### Stage 3 — CCC send-email action
-Extend `claude-code-conduit` with a `send-email` action (SMTP). Claude calls it as
-a tool with recipient, subject, and body.
+### ✅ Stage 3 — CCC send-email action
+`send-email` action already existed in `claude-code-conduit` with full SMTP,
+permission store, and topic-based access control. Tested and working end-to-end.
 
-### Stage 4 — Wire it together
-Replace the `inspect()` call with `make_prompt` + `send_to_claude`. End-to-end flow:
-email in → Claude processes → email out.
+### ✅ Stage 4 — Wire it together
+`make_prompt` + `send_to_claude` wired up. Full flow working:
+email in → Claude processes → replies via CCC send-email → email out.
 
 ### Stage 5 — Adaptive polling
 High/low frequency mode: switch to fast polling (e.g. 10s) when a message arrives,