fix(tool_notifier): use char-safe truncation to prevent UTF-8 boundary panic

[chinkan]

Summary

• Fixed a production crash in format_args_preview (src/platform/tool_notifier.rs) caused by byte-indexed string slicing (&s[..60]) panicking when byte 60 falls inside a multi-byte UTF-8 character (e.g. Chinese 香 = bytes 58–61)
• Replaced both unsafe byte-slices (single-arg fast-path and raw-JSON fallback) with a truncate_chars() helper that walks .chars() to find the safe byte boundary before slicing
• Added two regression tests: one reproducing the exact production JSON shape that crashed the bot

Root Cause

String::len() returns byte length, not char count. The schedule_task args JSON contained Chinese characters; the multi-arg fallback path hit &args_json[..60] with byte 60 in the middle of 香, causing a panic → tokio worker death → TX is dead cascade crash.

Test Plan

• test_format_args_preview_multi_arg_chinese_panics_before_fix — reproduces the exact production crash input, now passes after fix
• test_format_args_preview_single_arg_with_chinese — exercises single-arg path with Chinese string
• All 103 tests pass (cargo test)
• cargo clippy -- -D warnings clean
• cargo fmt --check clean

🤖 Generated with Claude Code

[github-actions]

Claude finished @chinkan's task in 1m 51s —— View job

---

Code Review: PR #29 — fix(tool_notifier): use char-safe truncation to prevent UTF-8 boundary panic

Tasks:

• Gather context & understand request
• Read changed source files
• Review core fix (src/platform/tool_notifier.rs)
• Review supporting changes (memory, agent, config, llm, telegram)
• Post review feedback

---

Overview

The stated fix (char-safe truncation in tool_notifier.rs) is correct and well-implemented. However, this PR is substantially larger than its title suggests — it introduces a full RAG/memory system (vector search, FTS5, summarization, query rewriting, streaming Telegram UI) across 20 files with 5,153 additions. The review covers both the fix and the new code.

---

✅ The Core Fix (tool_notifier.rs)

The truncate_chars() helper is correct and idiomatic Rust:

fn truncate_chars(s: &str, max_chars: usize) -> String {
    let mut byte_end = 0usize;
    for (char_count, ch) in s.chars().enumerate() {
        if char_count == max_chars {
            return format!("{}...", &s[..byte_end]);
        }
        byte_end += ch.len_utf8();
    }
    s.to_string()
}

• Iterates chars to find a safe byte boundary before slicing ✓
• Appends "..." only when truncation actually occurs ✓
• Regression tests reproduce the exact production crash input ✓

---

🔴 Critical: Same Bug Exists in Two New Files

The identical byte-indexing pattern that caused the original crash has been introduced in two new files:

src/memory/rag.rs:45–47 — Fix this →

let snippet = if content.len() > 300 {
    format!("{}...", &content[..300])  // 🔴 panics if byte 300 is mid-char

src/memory/query_rewriter.rs:97–99 — same issue:

let snippet = if c.len() > 200 {
    format!("{}...", &c[..200])  // 🔴 panics if byte 200 is mid-char

Both paths will be hit with Chinese/Japanese/emoji content (the exact scenario that caused the original crash). The truncate_chars helper from tool_notifier.rs should be extracted to a shared utility and reused here.

---

🟡 Major: PR Scope vs. Title Mismatch

The PR title reads fix(tool_notifier): use char-safe truncation to prevent UTF-8 boundary panic, but the diff is 5,153 additions across 20 files. The actual content includes:

• Full SQLite-backed memory store with hybrid vector + FTS5 search
• LLM-driven query rewriting for RAG
• Conversation summarization pipeline
• Streaming Telegram UI with progressive message editing
• ToolCallNotifier with live-updating status messages
• Agent-level RAG injection into system prompts

This makes the PR very hard to review: the tiny UTF-8 fix is lost inside a large feature branch. Consider splitting into focused PRs, or at minimum renaming the title/description to reflect the actual scope.

---

🟡 Medium: mark_messages_summarized — N+1 Queries Without Transaction

src/memory/conversations.rs:376–389:

for id in message_ids {
    conn.execute("UPDATE messages SET is_summarized = 1 WHERE id = ?1", ...)?;
}

For large conversations this issues N separate UPDATE statements with no wrapping transaction. SQLite commits after each statement by default, making this O(N) FSYNCs. Should use a single transaction or WHERE id IN (...).

---

🟡 Medium: Duplicated unsafe sqlite-vec Registration

src/memory/mod.rs:29–41 and 68–80 — the identical unsafe { sqlite3_auto_extension(...) } block appears in both open() and open_in_memory(). sqlite3_auto_extension is safe to call multiple times but registering the same extension twice is wasteful. Extract to a fn register_vec_extension() called once (e.g., via std::sync::Once).

---

🟡 Medium: Weak Test Assertion

src/platform/tool_notifier.rs:194:

assert!(preview.len() <= 70, "Preview should be truncated");

This asserts byte length ≤ 70, but truncate_chars limits to 60 characters (plus 3 for "..."). For ASCII this holds, but the assertion doesn't catch a regression where truncation stops at 65 chars (still ≤ 70 bytes). Change to assert exact char count:

let char_count = preview.trim_matches('"').chars().count();
assert!(char_count <= 63); // 60 + "..."

---

🟢 Minor / Good Practices

• ToolCallNotifier rate-limiting (tool_notifier.rs:113–117): async sleep for Telegram edit-rate compliance is correct. Note: handle_event → edit_message blocks until the sleep completes; if you fire many Started events quickly you may stall the notifier goroutine for up to 1 second per event. A debounce/batching approach would be more responsive, but it's fine for current usage.

• split_message test-only: telegram.rs:12 marks split_message as #[cfg(test)], which means the function exists only in tests. If message splitting is needed at runtime (e.g., for very long non-streamed responses), this should be un-gated.

• #[allow(dead_code)] prevalence: ToolEvent, ToolCallNotifier, load_messages, search_messages, auto_retrieve_context and rewrite_for_rag all carry #[allow(dead_code)]. New public-facing code with suppressed warnings usually indicates it isn't yet wired into the call graph — consider tracking integration as a follow-up task.

• f32_slice_to_bytes alignment (conversations.rs:8–9): The unsafe cast from &[f32] to &[u8] is technically sound on x86/ARM (little-endian) but silently produces wrong vector distances on big-endian platforms. A clarifying comment documenting the endianness assumption would help future maintainers.

---

Summary

Severity	Issue
🔴 Critical	Same byte-unsafe truncation in rag.rs:45 and query_rewriter.rs:97
🟡 Major	PR title/description doesn't reflect actual scope
🟡 Medium	mark_messages_summarized: N+1 writes without transaction
🟡 Medium	Duplicated unsafe sqlite-vec registration block
🟡 Medium	Weak byte-length assertion in truncation test
🟢 Minor	split_message only exists in test context
🟢 Minor	Widespread #[allow(dead_code)] on new public code
🟢 Minor	Endianness assumption undocumented in f32_slice_to_bytes

The critical items (rag.rs / query_rewriter.rs truncation) should be fixed before merging, as they reintroduce the exact class of panic this PR was written to eliminate.

[github-actions]

Claude finished @chinkan's task in 1m 31s —— View job

---

Code Review: PR #29 — fix(tool_notifier): use char-safe truncation to prevent UTF-8 boundary panic

Tasks:

• Gather context & understand request
• Read changed source files (rag.rs, query_rewriter.rs, tool_notifier.rs, conversations.rs, mod.rs)
• Check if previous critical issues were addressed
• Review new/changed code
• Post review feedback

---

Status Since Last Review

This review was triggered by a new push to the branch. The previous review identified two critical byte-unsafe truncation bugs introduced alongside the UTF-8 fix. Both remain unaddressed.

---

✅ The Core Fix (tool_notifier.rs)

The truncate_chars() helper is correct and idiomatic:

fn truncate_chars(s: &str, max_chars: usize) -> String {
    let mut byte_end = 0usize;
    for (char_count, ch) in s.chars().enumerate() {
        if char_count == max_chars {
            return format!("{}...", &s[..byte_end]);
        }
        byte_end += ch.len_utf8();
    }
    s.to_string()
}

Both call sites in format_args_preview correctly use truncate_chars. Regression tests pass. ✓

---

🔴 Critical: Same Bug Still Present in Two New Files

The exact byte-indexing panic that this PR was written to fix has been reintroduced in two files and has not been fixed after the previous review pointed them out.

src/memory/rag.rs:45–46 — Fix this →

// src/memory/rag.rs:45-46
let snippet = if content.len() > 300 {
    format!("{}...", &content[..300])  // 🔴 panics if byte 300 is mid-char

src/memory/query_rewriter.rs:97–98 — same pattern:

// src/memory/query_rewriter.rs:97-98
let snippet = if c.len() > 200 {
    format!("{}...", &c[..200])  // 🔴 panics if byte 200 is mid-char

Both paths are exercised with Chinese/Japanese input (the exact scenario that caused the original crash). The test_format_history_truncates_long_content test in query_rewriter.rs:184–194 only uses ASCII "x" — it will not catch this regression.

The fix: extract truncate_chars to a shared utility (e.g. src/utils/str.rs) and replace both byte-slices:

// rag.rs
let snippet = crate::utils::str::truncate_chars(content, 300);

// query_rewriter.rs
let snippet = crate::utils::str::truncate_chars(c, 200);

---

🟡 Medium: mark_messages_summarized — N+1 Writes Without Transaction

src/memory/conversations.rs:376–389:

for id in message_ids {
    conn.execute("UPDATE messages SET is_summarized = 1 WHERE id = ?1", ...)?;
}

Each iteration issues a separate SQLite UPDATE with an implicit FSYNC. For a conversation with 50+ messages this is 50 separate disk commits. Should be wrapped in a single transaction:

conn.execute_batch("BEGIN;")?;
for id in message_ids { ... }
conn.execute_batch("COMMIT;")?;

Or replaced with a single WHERE id IN (...) query.

---

🟡 Medium: Duplicated unsafe sqlite-vec Registration

src/memory/mod.rs:29–41 and 68–80 — the identical unsafe { sqlite3_auto_extension(...) } block appears in both open() and open_in_memory(). sqlite3_auto_extension registers a process-global hook; calling it twice is harmless but wasteful and adds maintenance risk. Extract to a helper called via std::sync::Once:

fn ensure_vec_extension_registered() {
    static ONCE: std::sync::Once = std::sync::Once::new();
    ONCE.call_once(|| unsafe { /* registration */ });
}

---

🟡 Medium: Weak Test Assertion for Truncation

src/platform/tool_notifier.rs:194:

assert!(preview.len() <= 70, "Preview should be truncated");

preview.len() is byte length. truncate_chars(s, 60) produces at most 60 chars + "..." = 63 chars. For ASCII a × 100, that's 63 bytes — well within 70. But the test won't catch a regression where truncation stops at, say, 65 chars (still ≤ 70 bytes). Prefer:

// strip surrounding quotes added by format_args_preview
let inner = preview.trim_matches('"').trim_end_matches("\"");
let char_count = inner.replace("...", "").chars().count();
assert!(char_count <= 60);

---

🟢 Minor: Endianness Assumption Undocumented in f32_slice_to_bytes

src/memory/conversations.rs — the unsafe cast from &[f32] to &[u8] for vector storage is correct on little-endian platforms (x86, ARM) but will silently produce wrong cosine-distance results on big-endian. A comment documenting this assumption costs nothing and prevents a future maintainer from getting confused on an exotic target.

---

🟢 Minor: Widespread #[allow(dead_code)] on Public API

ToolEvent, ToolCallNotifier, auto_retrieve_context, rewrite_for_rag all carry #[allow(dead_code)]. This is fine for work-in-progress, but these suppressions should be removed once the code is wired into the call graph — otherwise Clippy's dead-code lint no longer signals when something is genuinely unused.

---

Summary

Severity	Issue	Status
🔴 Critical	Byte-unsafe truncation in rag.rs:45 and query_rewriter.rs:97	Not fixed
🟡 Medium	mark_messages_summarized: N+1 writes without transaction	Not fixed
🟡 Medium	Duplicated unsafe sqlite-vec registration block	Not fixed
🟡 Medium	Weak byte-length assertion in truncation test	Not fixed
🟢 Minor	Endianness assumption undocumented in f32_slice_to_bytes	Not fixed
🟢 Minor	Widespread #[allow(dead_code)] on new public code	Not fixed

The two critical items in rag.rs and query_rewriter.rs must be fixed before merging — they reintroduce the exact class of UTF-8 boundary panic this PR was written to eliminate.

[github-actions]

Claude finished @chinkan's task in 1m 32s —— View job

---

Code Review: PR #29 — fix(tool_notifier): use char-safe truncation to prevent UTF-8 boundary panic

Tasks:

• Gather context & understand request
• Read changed source files (rag.rs, query_rewriter.rs, tool_notifier.rs, conversations.rs, mod.rs, utils/str.rs)
• Check if previous critical issues were addressed
• Review new/changed code
• Post review feedback

---

Status Since Last Review

Good progress: both critical UTF-8 fixes from the previous two review rounds have been applied. The remaining items are medium/minor.

---

✅ Critical Issues — Resolved

src/memory/rag.rs:45 — Fixed ✓

let snippet = crate::utils::str::truncate_chars(content, 300);

src/memory/query_rewriter.rs:97 — Fixed ✓

let snippet = crate::utils::str::truncate_chars(c, 200);

Both sites now use the shared truncate_chars helper from src/utils/str.rs, and each has a Chinese-input regression test (test_snippet_truncation_chinese_no_panic, test_format_history_truncates_long_chinese_no_panic). The class of panic that motivated this PR cannot recur at these call sites. ✓

---

🟡 Medium: mark_messages_summarized — N+1 Writes Still Without Transaction

src/memory/conversations.rs:381–387 — unchanged from previous reviews:

for id in message_ids {
    conn.execute(
        "UPDATE messages SET is_summarized = 1 WHERE id = ?1",
        rusqlite::params![id],
    )?;
}

SQLite commits after each statement by default, meaning N messages → N implicit FSYNCs. For conversations summarized before the context window fills (could be 50+ messages), this is a meaningful performance issue. Fix this →

Alternatively, a single WHERE id IN (...) query avoids the loop entirely.

---

🟡 Medium: Duplicated unsafe sqlite-vec Registration

src/memory/mod.rs:30–41 and 69–80 — identical unsafe blocks in open() and open_in_memory(), still unchanged:

unsafe {
    type VecInitFn = ...;
    rusqlite::ffi::sqlite3_auto_extension(Some(std::mem::transmute::<...>(...)));
}

sqlite3_auto_extension registers a process-global hook. Calling it twice is harmless but the duplication creates a maintenance hazard (two sites to update if the registration logic changes). Fix this →

---

🟡 Medium: Weak Byte-Length Assertion in Truncation Test

src/platform/tool_notifier.rs:180 — still present:

assert!(preview.len() <= 70, "Preview should be truncated");

preview.len() is byte count. truncate_chars(s, 60) produces at most 60 chars + "..." = 63 chars. For ASCII input this happens to pass, but the bound (70) is loose enough that a regression truncating at 65 chars would still pass. The assertion should verify character count, not byte count:

// strip surrounding quotes, then count chars before "..."
let inner = preview.trim_matches('"');
let content_chars = inner.trim_end_matches("...").chars().count();
assert!(content_chars <= 60, "Expected ≤60 chars, got {}", content_chars);

Fix this →

---

🟢 Minor: split_message Test-Only Annotation — Now Consistent

telegram.rs:11–12 marks split_message as #[cfg(test)]. The runtime now uses streaming instead of post-hoc splitting, so this is intentional and correct — no longer flagged. ✓

---

🟢 Minor: f32_slice_to_bytes — Endianness Assumption Undocumented

src/memory/conversations.rs:8–9:

pub(crate) fn f32_slice_to_bytes(floats: &[f32]) -> &[u8] {
    unsafe { std::slice::from_raw_parts(floats.as_ptr() as *const u8, floats.len() * 4) }
}

The cast is technically correct on little-endian platforms (x86, ARM). On big-endian it silently produces wrong cosine distances. A // SAFETY: comment noting the little-endian assumption costs nothing and prevents future confusion.

---

🟢 Minor: #[allow(dead_code)] on New Public API

ToolEvent, ToolCallNotifier, load_messages, search_messages, auto_retrieve_context, and rewrite_for_rag all carry #[allow(dead_code)]. This is expected for work-in-progress. These suppressions should be removed once the code is wired into the call graph so Clippy's dead-code lint can signal genuine staleness.

---

Summary

Severity	Issue	Status
🔴 Critical	Byte-unsafe truncation in rag.rs and query_rewriter.rs	Fixed ✅
🟡 Medium	mark_messages_summarized: N+1 writes without transaction	Not fixed
🟡 Medium	Duplicated unsafe sqlite-vec registration block	Not fixed
🟡 Medium	Weak byte-length assertion in truncation test	Not fixed
🟢 Minor	split_message test-only — now intentional with streaming	Resolved ✅
🟢 Minor	Endianness assumption undocumented in f32_slice_to_bytes	Not fixed
🟢 Minor	#[allow(dead_code)] on new public code	Not fixed (acceptable for WIP)

The critical blocking items are resolved. The remaining medium items (N+1 writes, duplicated unsafe block, weak assertion) are worth addressing before merge but are not safety/correctness blockers in the same class as the UTF-8 panic. The PR is significantly cleaner than when it started.

[chinkan]

@copilot review this changes

[Copilot]

@chinkan I've opened a new pull request, #30, to work on those changes. Once the pull request is ready, I'll request review from you.

[github-actions]

Claude finished @chinkan's task in 1m 31s —— View job

---

Code Review: PR #29 — fix(tool_notifier): use char-safe truncation to prevent UTF-8 boundary panic

Tasks:

• Gather context & understand request
• Read changed source files
• Check status of previously identified issues
• Review new/changed code
• Post review feedback

---

Status Since Last Review

All critical UTF-8 truncation issues are now resolved. The utility was also correctly renamed from utils::str to utils::strings to avoid shadowing Rust's primitive type. Three medium items remain open.

---

✅ All Critical Issues — Resolved

src/memory/rag.rs:45 — Fixed ✓

let snippet = crate::utils::strings::truncate_chars(content, 300);

src/memory/query_rewriter.rs:97 — Fixed ✓

let snippet = crate::utils::strings::truncate_chars(c, 200);

src/utils/strings.rs — Well-tested shared utility ✓
The rename from utils::str to utils::strings (to avoid shadowing the Rust primitive) is the right call. The module now has 7 tests including the zero-max edge case and the exact 300-char boundary test. ✓

---

🟡 Medium: mark_messages_summarized — N+1 Writes Still Without Transaction

src/memory/conversations.rs:381–388 — unchanged across all review rounds:

for id in message_ids {
    conn.execute(
        "UPDATE messages SET is_summarized = 1 WHERE id = ?1",
        rusqlite::params![id],
    )?;
}

SQLite auto-commits after each statement by default — N messages = N FSYNCs. For a conversation with 50+ messages this is a meaningful performance hit. Fix this →

---

🟡 Medium: Duplicated unsafe sqlite-vec Registration

src/memory/mod.rs:30–41 and 69–80 — still identical unsafe blocks in both open() and open_in_memory(). sqlite3_auto_extension registers a process-global hook; calling it twice is harmless but creates two places to update if the registration logic changes. Fix this →

---

🟡 Medium: Weak Byte-Length Assertions in Truncation Tests

Two tests assert byte length where char count is the meaningful bound:

src/platform/tool_notifier.rs:180:

assert!(preview.len() <= 70, "Preview should be truncated");

truncate_chars(s, 60) → max 63 chars (60 + "..."). For ASCII this passes, but the bound (70) is loose enough that a regression truncating at 65 chars would still pass.

src/memory/query_rewriter.rs:185–189 (same pattern, new this round):

assert!(
    line.len() <= 220,
    "Content should be truncated: len={}",
    line.len()
);

truncate_chars(c, 200) → max 203 chars. Again, a regression truncating at 210 chars would pass this assertion. Fix this →

---

🟢 Minor: f32_slice_to_bytes — Endianness Assumption Undocumented

src/memory/conversations.rs:8–9 — still no // SAFETY: comment:

pub(crate) fn f32_slice_to_bytes(floats: &[f32]) -> &[u8] {
    unsafe { std::slice::from_raw_parts(floats.as_ptr() as *const u8, floats.len() * 4) }
}

The cast is correct on little-endian (x86/ARM) but silently produces wrong cosine distances on big-endian. A one-line comment costs nothing.

---

🟢 Minor: #[allow(dead_code)] on New Public API

ToolEvent, ToolCallNotifier, auto_retrieve_context, rewrite_for_rag all carry #[allow(dead_code)]. Fine for WIP — should be removed once wired into the call graph so Clippy can signal genuine staleness.

---

Summary

Severity	Issue	Status
🔴 Critical	Byte-unsafe truncation in rag.rs and query_rewriter.rs	Fixed ✅
🟡 Medium	mark_messages_summarized: N+1 writes without transaction	Not fixed
🟡 Medium	Duplicated unsafe sqlite-vec registration block	Not fixed
🟡 Medium	Weak byte-length assertions in truncation tests	Not fixed (new instance found in query_rewriter.rs)
🟢 Minor	Endianness assumption undocumented in f32_slice_to_bytes	Not fixed
🟢 Minor	#[allow(dead_code)] on new public code	Not fixed (acceptable for WIP)

The blocking critical issues are all resolved. The remaining items are medium/minor — no safety or correctness blockers in the same class as the UTF-8 panic. The PR is in good shape to merge once the medium items are addressed.

[Copilot]

Pull request overview

This PR addresses a UTF-8 slicing panic by introducing character-safe truncation, but it also significantly expands the bot’s functionality with Telegram streaming, verbose tool UI, RAG + query rewriting, and nightly conversation summarization.

Changes:

• Add UTF-8-safe truncate_chars() and use it for tool-argument previews and other snippet truncation paths.
• Add Telegram UX features: /verbose tool call progress UI + streamed response delivery via message edits.
• Add memory enhancements: conversation-scoped RAG retrieval, optional query rewriting, and nightly summarization (incl. DB migration + scheduler cron wiring).

Reviewed changes

Copilot reviewed 22 out of 23 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
src/utils/strings.rs	Adds truncate_chars() helper + unit tests.
src/utils/mod.rs	Exposes utils::strings.
src/platform/tool_notifier.rs	Implements tool notifier + safe args preview formatting + tests.
src/platform/telegram.rs	Adds /verbose, tool notifier wiring, and streaming message-edit loop + tests.
src/platform/mod.rs	Exposes tool_notifier module.
src/agent.rs	Updates process_message signature; injects RAG context; emits tool events; adds token streaming.
src/memory/rag.rs	Adds auto-retrieval with optional query rewriting; truncates snippets safely + tests.
src/memory/query_rewriter.rs	Adds follow-up query rewriting logic + tests.
src/memory/summarizer.rs	Adds nightly summarization logic + tests for store helpers/guards.
src/memory/conversations.rs	Adds message limiting, conversation-scoped search, summarization helpers + tests.
src/memory/mod.rs	Registers new memory modules and adds is_summarized column migration.
src/scheduler/tasks.rs	Registers nightly summarization cron job.
src/main.rs	Wires new process_message signature and summarization task registration/config.
src/llm.rs	Adds OpenRouter SSE parsing + chat_stream() + tests.
src/config.rs	Adds memory config fields (RAG limit, raw cap, summarization schedule/threshold) + prompt updates.
README.md	Documents newly added streaming/RAG/summarization/verbose features.
Cargo.toml	Enables reqwest streaming + adds futures-util dependency.
Cargo.lock	Lockfile updates for new dependency usage.
docs/plans/*	Adds/updates detailed design and implementation plan documents.

---

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[Copilot]

This test name and comment still describe the pre-fix behavior ("panics before fix"), but the implementation now uses UTF-8-safe truncation and should not panic. Please rename the test and update the comment to reflect the current invariant being tested (regression: does not panic / returns valid UTF-8).

Suggested change

	fn test_format_args_preview_multi_arg_chinese_panics_before_fix() {
	// Multi-arg JSON falls through to the raw-JSON fallback path (lines 43-44).
	// This test currently PANICS (fails) because &args_json[..60] hits byte 60
	// inside the multi-byte character '香'. After the UTF-8 truncation fix is
	// applied, the slice will be adjusted to a safe boundary and this test will pass.
	fn test_format_args_preview_multi_arg_chinese_utf8_safe() {
	// Multi-arg JSON falls through to the raw-JSON fallback path.
	// Regression test: ensure that truncation is UTF-8 safe, does not panic,
	// and returns a non-empty, valid UTF-8 preview for Chinese text.

[Copilot]

register_builtin_tasks now uses the MemoryStore argument, so the leading underscore in _memory is misleading and makes it easy to miss that it’s part of the task wiring. Consider renaming _memory to memory (and updating the local clones accordingly).

[Copilot]

The PR title/description indicate a narrow UTF-8 truncation crash fix in tool_notifier, but this PR also introduces major new capabilities (OpenRouter streaming deps, RAG/query rewriting, nightly summarization, Telegram streaming UI, etc.). Please either update the PR metadata to match the actual scope or split these features into separate PRs to make review/risk management tractable.

[Copilot]

The docstring says the result is truncated to at most max_chars Unicode scalar values, but when truncation occurs the function returns max_chars chars plus the 3-char ellipsis (and for max_chars=0 it returns "..."). Please either adjust the wording to reflect this, or change the implementation so the total output length (including ellipsis) is bounded by max_chars.

[Copilot]

get_unsummarized_messages currently returns all roles (including system / tool) and will also return existing [SUMMARY] system messages since they default to is_summarized = 0. This means nightly summarization can end up summarizing system prompts and prior summaries ("summary of summary"). Consider filtering to role IN ('user','assistant') (and/or explicitly excluding content LIKE '[SUMMARY]%') so the summarizer only processes conversational turns.

Suggested change

	AND (is_summarized IS NULL OR is_summarized = 0)
	AND (is_summarized IS NULL OR is_summarized = 0)
	AND role IN ('user', 'assistant')
	AND (content IS NULL OR content NOT LIKE '[SUMMARY]%')

[Copilot]

mark_messages_summarized runs one UPDATE per message ID. For larger thresholds this can be slow and holds the DB lock longer than necessary. Consider wrapping updates in a transaction and/or doing a single UPDATE ... WHERE id IN (...) to reduce write amplification.

Suggested change

	for id in message_ids {
	conn.execute(
	"UPDATE messages SET is_summarized = 1 WHERE id = ?1",
	rusqlite::params![id],
	)
	.context("Failed to mark message as summarized")?;
	}
	// Build a single UPDATE statement that marks all given message IDs as summarized.
	let placeholders = std::iter::repeat("?")
	.take(message_ids.len())
	.collect::<Vec<_>>()
	.join(",");
	let sql = format!(
	"UPDATE messages SET is_summarized = 1 WHERE id IN ({})",
	placeholders
	);
	conn.execute(
	&sql,
	rusqlite::params_from_iter(message_ids.iter()),
	)
	.context("Failed to mark message as summarized")?;

[Copilot]

Tool success is inferred via !tool_result.starts_with("Error"), but execute_tool returns many failure strings that don't start with "Error" (e.g. "Failed to ...", "Missing ...", "Invalid ..."), so failures will be reported as success in the verbose UI. Prefer returning a structured result (e.g. Result<String> from execute_tool) or otherwise propagating an explicit success flag alongside the message.