cleanup: fix all build warnings, delete dead DMN context code

- Delete poc-daemon/src/context.rs dead code (git_context, work_state,
  irc_digest, recent_commits, uncommitted_files) — replaced by
  where-am-i.md and memory graph
- Remove unused imports (BufWriter, Context, similarity)
- Prefix unused variables (_store, _avg_cc, _episodic_ratio, _message)
- #[allow(dead_code)] on public API surface that's not yet wired
  (Message::assistant, ConversationLog::message_count/read_all,
  Config::context_message, ContextInfo fields)
- Fix to_capnp macro dead_code warning
- Rename _rewrite_store_DISABLED to snake_case

Only remaining warnings are in generated capnp code (can't fix).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

poc-agent/src/agent.rs

@@ -1066,15 +1066,15 @@ struct ContextPlan {
     /// Index into recent conversation: skip messages before this
     conv_trim: usize,
     /// Total recent conversation messages
-    conv_count: usize,
+    _conv_count: usize,
     /// Tokens used by full journal entries
-    full_tokens: usize,
+    _full_tokens: usize,
     /// Tokens used by header-only journal entries
-    header_tokens: usize,
+    _header_tokens: usize,
     /// Tokens used by conversation (after trimming)
-    conv_tokens: usize,
+    _conv_tokens: usize,
     /// Total budget available (after identity, memory, reserve)
-    available: usize,
+    _available: usize,
 }
 
 /// Build a context window from conversation messages + journal entries.
@@ -1233,11 +1233,11 @@ fn plan_context(
         full_start,
         entry_count: entries.len(),
         conv_trim,
-        conv_count: recent.len(),
-        full_tokens: full_used,
-        header_tokens: header_used,
-        conv_tokens: trimmed_conv,
-        available,
+        _conv_count: recent.len(),
+        _full_tokens: full_used,
+        _header_tokens: header_used,
+        _conv_tokens: trimmed_conv,
+        _available: available,
     }
 }
 

poc-agent/src/api/mod.rs

@@ -14,7 +14,7 @@
 mod anthropic;
 mod openai;
 
-use anyhow::{Context, Result};
+use anyhow::Result;
 use reqwest::Client;
 use std::time::{Duration, Instant};
 

poc-agent/src/api/openai.rs

@@ -62,7 +62,7 @@ pub async fn stream(
     let mut empty_deltas: u64 = 0;
     let mut first_content_at: Option<Duration> = None;
 
-    let reasoning_enabled = reasoning_effort != "none";
+    let _reasoning_enabled = reasoning_effort != "none";
 
     while let Some(event) = reader.next_event(&mut response).await? {
         // OpenRouter sometimes embeds error objects in the stream

poc-agent/src/config.rs

@@ -220,6 +220,7 @@ pub struct Config {
 
 impl Config {
     /// Join context parts into a single string for legacy interfaces.
+    #[allow(dead_code)]
     pub fn context_message(&self) -> String {
         self.context_parts.iter()
             .map(|(name, content)| format!("## {}\n\n{}", name, content))

poc-agent/src/log.rs

@@ -80,6 +80,7 @@ impl ConversationLog {
     }
 
     /// Count messages in the log without loading content.
+    #[allow(dead_code)]
     pub fn message_count(&self) -> Result<usize> {
         if !self.path.exists() {
             return Ok(0);
@@ -94,6 +95,7 @@ impl ConversationLog {
 
     /// Read all messages from the log. Returns empty vec if log doesn't exist.
     /// NOTE: Don't use this in hot paths — use read_tail() instead.
+    #[allow(dead_code)]
     pub fn read_all(&self) -> Result<Vec<Message>> {
         if !self.path.exists() {
             return Ok(Vec::new());

poc-agent/src/types.rs

@@ -280,6 +280,7 @@ impl Message {
         }
     }
 
+    #[allow(dead_code)]
     pub fn assistant(content: impl Into<String>) -> Self {
         Self {
             role: Role::Assistant,

poc-agent/src/ui_channel.rs

@@ -63,7 +63,9 @@ pub struct ContextInfo {
     pub available_models: Vec<String>,
     pub prompt_file: String,
     pub backend: String,
+    #[allow(dead_code)]
     pub instruction_files: Vec<(String, usize)>,
+    #[allow(dead_code)]
     pub memory_files: Vec<(String, usize)>,
     pub system_prompt_chars: usize,
     pub context_message_chars: usize,