feat: vision in the agentic chat path (image content block)

handle_chat_agentic now reads body image + image_media_type and, when present, sends the current
user turn as an Anthropic content-block array [{text},{image}] instead of a plain string — so the
model sees raw pixels alongside memory, history, and tools (parity with the CLI). Additive: no image
=> output byte-identical to before. elc-clean. Pairs with neuron-ui fix/chat-vision-attachments.

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

PREVENTION-FIXES-FOR-REVIEW.md

@@ -1,52 +0,0 @@
-# Prevention fixes for review (engram corruption at the source) — for Will
-
-**Context:** a scan of Tim's engram found 21% of nodes corrupt. Root cause is **boot-time writes that
-re-insert instead of update**, plus no UTF-8 validation. New users start clean but would rot the same way.
-Full spec: `docs/research-archive/p0-prototypes/CORRUPTION-PREVENTION-SPEC.md`. These are **soul core**, so
-this is a proposal for your review/build/test — nothing applied. Prepared by Neuron-in-the-CLI (untested El;
-needs your engram-internals knowledge to finalize).
-
-## The one question that unblocks everything
-**Does `engram_node_full(content, type, label, …)` upsert by label, or always insert a new node?**
-- `conv_history_persist` (chat.el:786) reuses label `"conv:history"` and is described as "upsert by label",
-  and does NOT show up as heavy duplicates.
-- `mem_boot_count_inc` (memory.el:127) reuses label `"soul:boot_count"` but **accumulated ~120 copies**.
-- Both call `engram_node_full` with a fixed label + changing content. If it upserts by label, boot_count
-  shouldn't accumulate; since it does, either it inserts, or conv:history avoids dups another way.
-- **Your answer decides the fix:** (a) if there's an upsert/update-by-label primitive, the fixes are
-  one-line swaps; (b) if not, we add a `find-by-label → update-or-insert` helper and use it everywhere.
-
-`engram_node_full` / `engram_get_node_by_label` / any update primitive live in the engram repo — couldn't
-inspect their semantics from the soul repo.
-
-## FIX 1 — Idempotent boot seeding (biggest cause, ~75% of corruption)
-- **`mem_boot_count_inc` (memory.el:127-140)** — the code comment admits it: *"Each boot creates a new
-  'soul:boot_count:N' node. Old ones accumulate as history."* → change to **update the single
-  `soul:boot_count` node** (find-by-label → set content to new count), not create a new one.
-- **Identity/safety belief seeding** (the `safety:*-boundary`, `safety:anti-hallucination` beliefs that hit
-  ~81 copies each) — wherever these are seeded on boot, make them **upsert by label** so re-seeding updates
-  the one node instead of adding a copy. (Reuse the `chat.el` "upsert by label" approach.)
-- **Test:** boot the clean profile (:7798) 5×; each `safety:*-boundary` belief and `soul:boot_count` exists
-  exactly **once**; counter shows the latest value.
-
-## FIX 2 — UTF-8 validation/sanitization on every engram write
-- No UTF-8 validation found on the write path; invalid bytes got persisted (garbled nodes).
-- **Fix:** validate/normalize to valid UTF-8 before `engram_node_full` persists (reject or sanitize).
-- **Test:** write a node with invalid bytes → stored clean (or rejected); snapshot parses with zero
-  replacement characters.
-
-## FIX 3 — Confirm read-back-verify covers ALL write paths
-- Already present: `api_persisted` ("read-back-after-write guard", neuron-api.el:90) + safety.el:410. Good.
-- **Review the deliberate exception** at neuron-api.el:198 ("NOT read-back-verify here … can return a STALE
-  hit for a just-written node") and close it safely so every write path verifies.
-- **Test:** save → read back → matches; force a failed write → returns `api_not_persisted`, not false success.
-
-## FIX 4 — Cap/prune time-series events (housekeeping, NOT corruption)
-- The ~120 `session-start` InternalStateEvent nodes (soul.el:294) are **legitimate per-boot history** — do
-  **not** dedup them. But keep them bounded (keep last N / summarize older) so the engram doesn't grow forever.
-- **Test:** after many boots, event count stays bounded; older history still summarized.
-
-## Sequence
-Confirm the upsert question → implement Fix 1 (biggest win) → Fix 2 → Fix 3 → Fix 4 → build + test on the
-clean profile (:7798) before prod. Legacy cleanup of existing corrupt data is a **separate, secondary**
-safety net (and its dedup must be time-series-aware + merge edges, not blind-delete).

chat.el

@@ -1688,12 +1688,25 @@ fn handle_chat_agentic(body: String) -> String {
     let safe_msg: String = json_safe(message)
     let safe_sys: String = json_safe(system)
 
+    // Vision in the agentic brain (2026-06-27): when the client attaches an image
+    // (base64 in body "image", mime in "image_media_type"), send it as a real Anthropic
+    // image content block on THIS user turn — so the model sees raw pixels WITH memory,
+    // history, and tools (parity with the CLI). img_b64 == "" => byte-identical to before.
+    let img_b64: String = json_get(body, "image")
+    let img_mt_raw: String = json_get(body, "image_media_type")
+    let img_mt: String = if str_eq(img_mt_raw, "") { "image/png" } else { img_mt_raw }
+    let cur_user_content: String = if str_eq(img_b64, "") {
+        "\"" + safe_msg + "\""
+    } else {
+        "[{\"type\":\"text\",\"text\":\"" + safe_msg + "\"},{\"type\":\"image\",\"source\":{\"type\":\"base64\",\"media_type\":\"" + img_mt + "\",\"data\":\"" + img_b64 + "\"}}]"
+    }
+
     // Seed the messages array with recent history if available, so the LLM sees the thread.
     let prior_messages: String = if agentic_hist_len > 0 {
         let inner: String = str_slice(agentic_hist, 1, str_len(agentic_hist) - 1)
-        "[" + inner + ",{\"role\":\"user\",\"content\":\"" + safe_msg + "\"}]"
+        "[" + inner + ",{\"role\":\"user\",\"content\":" + cur_user_content + "}]"
     } else {
-        "[{\"role\":\"user\",\"content\":\"" + safe_msg + "\"}]"
+        "[{\"role\":\"user\",\"content\":" + cur_user_content + "}]"
     }
     let messages: String = prior_messages
     let api_url: String = "https://api.anthropic.com/v1/messages"