add observer agent: read-only watcher with git-based feeder script

- observer.json: read-only tool set (file_read, file_grep, file_glob, reasoning_think)
- agent-observer.md: terse observation-only prompt
- observer-feed: polls git diff, feeds changes to agent prompt
- justfile: install new files

data/agents/observer.json

@@ -0,0 +1,14 @@
+{
+  "prompt": [
+    "$XDG_CONFIG_HOME/ollie/prompts/agent-observer.md"
+  ],
+  "autoLoad": [
+    "reasoning_think",
+    "file_read",
+    "file_glob",
+    "file_grep"
+  ],
+  "maxSteps": 5,
+  "temperature": 0.3,
+  "maxTokens": 4096
+}

data/prompts/agent-observer.md

@@ -0,0 +1,34 @@
+# Observer
+
+You are a code observer. You watch a developer's changes in real-time and provide brief, useful observations.
+
+## Role
+
+- You receive diffs as they happen — staged and unstaged changes in a git repository.
+- You observe patterns, spot bugs, note style issues, flag logic errors, and catch missed edge cases.
+- You do NOT make changes. You have no write tools. You are read-only.
+
+## Output rules
+
+- Be terse. One to three sentences per observation. No preamble.
+- Only speak when you have something genuinely useful to say. Silence is fine.
+- If a diff is trivial (whitespace, formatting, rename), say nothing.
+- Focus on: correctness bugs, security issues, missed error handling, race conditions, broken invariants.
+- Do NOT repeat yourself. If you already noted something, don't note it again.
+- Do NOT suggest rewrites or provide code unless specifically asked.
+
+## Context
+
+Each message you receive is a `git diff` snapshot. The diff shows what the developer just changed. You may use your read-only tools to look at surrounding code for context if the diff alone is ambiguous.
+
+## Examples
+
+Good observations:
+- "The new error path on line 34 doesn't release the lock acquired on line 28."
+- "This nil check is inverted — it'll panic on the happy path."
+- "The SQL query interpolates user input directly. Use a parameterized query."
+
+Bad observations (don't do this):
+- "Nice refactor!" (empty praise)
+- "You might want to consider..." (hedging)
+- "Here's how I'd rewrite this: ..." (unsolicited rewrites)

data/scripts/observer-feed

@@ -0,0 +1,66 @@
+#!/bin/bash
+# observer-feed — watches git repo for changes and feeds diffs to an observer agent.
+#
+# Usage: observer-feed <session>/<agent> [interval]
+#
+# Watches the git working tree. When the diff changes, pushes the new diff
+# to the agent's prompt. Runs until killed.
+#
+# Arguments:
+#   session/agent   Target agent (e.g., myproj/observer)
+#   interval        Poll interval in seconds (default: 5)
+#
+# The agent should be created first:
+#   o myproj/observer new /path/to/repo
+#
+# Environment:
+#   Respects the repo at the agent's cwd. Falls back to $PWD.
+
+set -euo pipefail
+
+if [[ $# -lt 1 ]]; then
+    echo "usage: observer-feed <session>/<agent> [interval]" >&2
+    exit 1
+fi
+
+TARGET="$1"
+INTERVAL="${2:-5}"
+
+# Parse session/agent
+if [[ "$TARGET" != */* ]]; then
+    echo "error: must specify session/agent (e.g., myproj/observer)" >&2
+    exit 1
+fi
+
+SESSION="${TARGET%%/*}"
+AGENT="${TARGET#*/}"
+PROMPT_PATH="session/$SESSION/agent/$AGENT/prompt"
+
+# Get the agent's cwd for the git repo
+CWD=$(ollie-9p read "session/$SESSION/agent/$AGENT/cfg" 2>/dev/null | grep '^cwd=' | cut -d= -f2-)
+if [[ -z "$CWD" ]]; then
+    CWD="$PWD"
+fi
+
+cd "$CWD"
+
+if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+    echo "error: $CWD is not a git repository" >&2
+    exit 1
+fi
+
+echo "[observer-feed] watching $CWD every ${INTERVAL}s → $TARGET"
+
+LAST_DIFF=""
+
+while true; do
+    # Capture current diff (unstaged + staged vs HEAD)
+    DIFF=$(git diff HEAD -- 2>/dev/null || true)
+
+    if [[ -n "$DIFF" && "$DIFF" != "$LAST_DIFF" ]]; then
+        printf '%s\n' "$DIFF" | ollie-9p write "$PROMPT_PATH"
+        LAST_DIFF="$DIFF"
+    fi
+
+    sleep "$INTERVAL"
+done

justfile

@@ -92,7 +92,7 @@ install-el:
 migrate-bin:
     #!/usr/bin/env sh
     old="$HOME/bin"
-    for f in olliesrv ollie-9p ollie-remote toolsrv ollie-gui ollie-remount logseq-cli o; do
+    for f in olliesrv ollie-9p ollie-remote toolsrv ollie-gui ollie-remount logseq-cli o observer-feed; do
         if [ -f "$old/$f" ]; then
             echo "  removing stale $old/$f"
             rm -f "$old/$f"
@@ -114,6 +114,7 @@ install-data:
     install -m644 data/agents/README.md {{cfg}}/agents/README.md
     install -m644 data/agents/taskmanager.json {{cfg}}/agents/taskmanager.json
     install -m644 data/agents/theo.json {{cfg}}/agents/theo.json
+    install -m644 data/agents/observer.json {{cfg}}/agents/observer.json
     # Prompts
     mkdir -p {{cfg}}/prompts
     mkdir -p {{cfg}}/memory
@@ -124,6 +125,7 @@ install-data:
     install -m644 data/prompts/agent-navigator.md {{cfg}}/prompts/agent-navigator.md
     install -m644 data/prompts/agent-taskmanager.md {{cfg}}/prompts/agent-taskmanager.md
     install -m644 data/prompts/agent-theo.md {{cfg}}/prompts/agent-theo.md
+    install -m644 data/prompts/agent-observer.md {{cfg}}/prompts/agent-observer.md
     install -m644 data/prompts/user-preferences.md {{cfg}}/prompts/user-preferences.md
     # Sandbox
     install -m644 cmd/toolsrv/internal/sandbox/sandbox.yaml {{cfg}}/sandbox.yaml
@@ -182,11 +184,12 @@ install-data:
     install -m644 data/tools/_lib/__init__.py {{cfg}}/tools/_lib/__init__.py
     install -m644 data/tools/_lib/args.py {{cfg}}/tools/_lib/args.py
     install -m755 data/tools/_lib/args.sh {{cfg}}/tools/_lib/args.sh
-    # Scripts (ollie-remount, logseq-cli, o)
+    # Scripts (ollie-remount, logseq-cli, o, observer-feed)
     mkdir -p {{bin}}
     install -m755 data/scripts/ollie-remount {{bin}}/ollie-remount
     install -m755 data/scripts/logseq-cli {{bin}}/logseq-cli
     install -m755 data/scripts/o {{bin}}/o
+    install -m755 data/scripts/observer-feed {{bin}}/observer-feed
     # Acme scripts
     install -m755 data/scripts/acme/acme-ollie-ensure {{bin}}/acme-ollie-ensure
     install -m755 data/scripts/acme/AskFile {{bin}}/AskFile