feat(acp): inject requester git email into [Context] for commit trailers

Agents currently fall back to `git config user.email` for commit trailers,
which resolves to the repo owner's identity — not the human who triggered
the turn. NIP-01 kind:0 already has a standard `email` field; this change
stores it and surfaces it in every prompt so agents can use the correct
identity.

- Add nullable `git_email` column to `users` table (migration 0004)
- Parse the NIP-01 `email` field from kind:0 events in `handle_kind0_profile`
  and store it via `update_user_profile`
- Add `git_email` to `PromptProfile`; parse it in `parse_kind0_profile_lookup`
- Emit `Requester-Git-Email: Name <email>` in `[Context]` when the triggering
  event's author has a git_email set; omit the line entirely when absent
- Update `nest_agents.md`: prefer `Requester-Git-Email:` from `[Context]`
  over `git config user.email`; fall back to git config when absent

Co-authored-by: Will Pfleger <pfleger.will@gmail.com>
Signed-off-by: Will Pfleger <pfleger.will@gmail.com>

Author: npub1mn7jgtj4w2pd0g0zeuhxsa6jy6p0rewxz4kujt98my82ahfmp72sxjexk7

crates/buzz-acp/src/pool.rs

@@ -1648,7 +1648,7 @@ fn profile_event_is_agent(ev: &serde_json::Value) -> bool {
 /// Parse kind:0 profile events into a `PromptProfileLookup`.
 ///
 /// Each kind:0 event has `pubkey` and JSON `content` with optional fields:
-/// `display_name` (or `name`), `nip05`.
+/// `display_name` (or `name`), `nip05`, `email`.
 fn parse_kind0_profile_lookup(json: serde_json::Value) -> Option<PromptProfileLookup> {
     let events = json.as_array()?;
     let mut lookup = PromptProfileLookup::new();
@@ -1667,13 +1667,19 @@ fn parse_kind0_profile_lookup(json: serde_json::Value) -> Option<PromptProfileLo
                     .get("nip05")
                     .and_then(|v| v.as_str())
                     .map(str::to_string);
+                let git_email = profile
+                    .get("email")
+                    .and_then(|v| v.as_str())
+                    .filter(|s| !s.is_empty())
+                    .map(str::to_string);
                 let is_agent = profile_event_is_agent(ev);
                 lookup.insert(
                     pk.to_ascii_lowercase(),
                     PromptProfile {
                         display_name,
                         nip05_handle,
                         is_agent,
+                        git_email,
                     },
                 );
             }
@@ -2805,6 +2811,7 @@ mod tests {
                 display_name: Some("Wes".into()),
                 nip05_handle: Some("wes@example.com".into()),
                 is_agent: false,
+                git_email: None,
             })
         );
     }
@@ -2837,6 +2844,46 @@ mod tests {
         assert!(parse_kind0_profile_lookup(json!({})).is_none());
     }
 
+    #[test]
+    fn test_parse_kind0_profile_lookup_extracts_email() {
+        let lookup = parse_kind0_profile_lookup(json!([
+            {
+                "pubkey": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+                "kind": 0,
+                "content": "{\"display_name\":\"Will\",\"email\":\"will@example.com\"}",
+                "created_at": 1000,
+                "tags": []
+            }
+        ]))
+        .expect("lookup should parse");
+
+        let profile = lookup
+            .get("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
+            .expect("profile should be present");
+        assert_eq!(profile.git_email, Some("will@example.com".into()));
+        assert_eq!(profile.display_name, Some("Will".into()));
+    }
+
+    #[test]
+    fn test_parse_kind0_profile_lookup_ignores_empty_email() {
+        let lookup = parse_kind0_profile_lookup(json!([
+            {
+                "pubkey": "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
+                "kind": 0,
+                "content": "{\"display_name\":\"Bob\",\"email\":\"\"}",
+                "created_at": 1000,
+                "tags": []
+            }
+        ]))
+        .expect("lookup should parse");
+
+        let profile = lookup
+            .get("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb")
+            .expect("profile should be present");
+        // Empty email string should be treated as absent (None).
+        assert_eq!(profile.git_email, None);
+    }
+
     #[test]
     fn test_json_to_context_message_missing_pubkey_uses_default() {
         let obj = json!({ "content": "hello" });

crates/buzz-acp/src/queue.rs

@@ -740,6 +740,9 @@ pub struct PromptProfile {
     /// i.e. it is an owned agent rather than a human. Used to gate reply-anchor
     /// flattening (UX routing heuristic, not a security boundary).
     pub is_agent: bool,
+    /// Git email from the NIP-01 kind:0 `email` field. Injected into `[Context]`
+    /// as `Requester-Git-Email:` so agents can use it for commit trailers.
+    pub git_email: Option<String>,
 }
 
 /// Pubkey-keyed profile lookup used while formatting ACP prompts.
@@ -966,12 +969,30 @@ fn format_context_hints(
     is_dm: bool,
     has_conversation_context: bool,
     reply_anchor: Option<&str>,
+    sender_pubkey: &str,
+    profile_lookup: Option<&PromptProfileLookup>,
 ) -> String {
     let channel_display = match channel_info {
         Some(ci) => format!("{} (#{channel_id})", ci.name),
         None => channel_id.to_string(),
     };
 
+    // Emit `Requester-Git-Email: Name <email>` when the triggering event's author
+    // has a git_email set in their profile. Agents use this for commit trailers
+    // instead of falling back to `git config user.email`.
+    let requester_git_email_line = profile_lookup
+        .and_then(|lookup| lookup.get(&normalize_lookup_key(sender_pubkey)))
+        .and_then(|profile| {
+            let email = profile.git_email.as_deref()?;
+            let name = profile
+                .display_name
+                .as_deref()
+                .or(profile.nip05_handle.as_deref())
+                .unwrap_or("Unknown");
+            Some(format!("\nRequester-Git-Email: {name} <{email}>"))
+        })
+        .unwrap_or_default();
+
     // DM check comes first — a DM reply has both thread tags AND is_dm=true,
     // and the scope should be "dm" (not "thread") because the agent is in a DM.
     if is_dm {
@@ -1005,6 +1026,7 @@ fn format_context_hints(
                 append_reply_instruction(&mut s, event_id);
             }
         }
+        s.push_str(&requester_git_email_line);
         s
     } else if let Some(ref root) = thread_tags.root_event_id {
         let ctx_hint = if has_conversation_context {
@@ -1027,6 +1049,7 @@ fn format_context_hints(
         if let Some(event_id) = reply_anchor {
             append_reply_instruction(&mut s, event_id);
         }
+        s.push_str(&requester_git_email_line);
         s
     } else {
         let mut s = format!(
@@ -1038,6 +1061,7 @@ fn format_context_hints(
         if let Some(event_id) = reply_anchor {
             append_new_thread_reply_instruction(&mut s, event_id);
         }
+        s.push_str(&requester_git_email_line);
         s
     }
 }
@@ -1194,6 +1218,8 @@ pub fn format_prompt(batch: &FlushBatch, args: &FormatPromptArgs<'_>) -> Vec<Str
         is_dm,
         args.conversation_context.is_some(),
         reply_anchor.as_deref(),
+        &sender_pubkey,
+        args.profile_lookup,
     ));
 
     // 3. Conversation context (thread or DM).
@@ -3506,4 +3532,97 @@ mod tests {
             None
         );
     }
+
+    // ── Requester-Git-Email injection ────────────────────────────────────────
+
+    /// When the triggering event's author has a git_email in their profile,
+    /// `[Context]` should include a `Requester-Git-Email:` line.
+    #[test]
+    fn test_format_context_hints_emits_requester_git_email_when_present() {
+        let batch = make_single_batch("hello");
+        let sender_hex = batch.events[0].event.pubkey.to_hex();
+        let profiles = HashMap::from([(
+            sender_hex.clone(),
+            PromptProfile {
+                display_name: Some("Will Pfleger".into()),
+                git_email: Some("will@example.com".into()),
+                ..Default::default()
+            },
+        )]);
+
+        let prompt = format_prompt(
+            &batch,
+            &FormatPromptArgs {
+                profile_lookup: Some(&profiles),
+                ..Default::default()
+            },
+        )
+        .join("\n\n");
+
+        assert!(
+            prompt.contains("Requester-Git-Email: Will Pfleger <will@example.com>"),
+            "context block should include Requester-Git-Email when profile has git_email"
+        );
+    }
+
+    /// When the triggering event's author has no git_email, `[Context]` must
+    /// NOT include a `Requester-Git-Email:` line.
+    #[test]
+    fn test_format_context_hints_omits_requester_git_email_when_absent() {
+        let batch = make_single_batch("hello");
+        let sender_hex = batch.events[0].event.pubkey.to_hex();
+        let profiles = HashMap::from([(
+            sender_hex.clone(),
+            PromptProfile {
+                display_name: Some("Will Pfleger".into()),
+                git_email: None,
+                ..Default::default()
+            },
+        )]);
+
+        let prompt = format_prompt(
+            &batch,
+            &FormatPromptArgs {
+                profile_lookup: Some(&profiles),
+                ..Default::default()
+            },
+        )
+        .join("\n\n");
+
+        assert!(
+            !prompt.contains("Requester-Git-Email"),
+            "context block should not include Requester-Git-Email when git_email is absent"
+        );
+    }
+
+    /// Falls back to display_name when constructing the Requester-Git-Email line.
+    /// When display_name is absent, nip05_handle is used as the name part.
+    #[test]
+    fn test_format_context_hints_requester_git_email_uses_nip05_as_name_fallback() {
+        let batch = make_single_batch("hello");
+        let sender_hex = batch.events[0].event.pubkey.to_hex();
+        let profiles = HashMap::from([(
+            sender_hex.clone(),
+            PromptProfile {
+                display_name: None,
+                nip05_handle: Some("will@relay.example.com".into()),
+                git_email: Some("will@example.com".into()),
+                ..Default::default()
+            },
+        )]);
+
+        let prompt = format_prompt(
+            &batch,
+            &FormatPromptArgs {
+                profile_lookup: Some(&profiles),
+                ..Default::default()
+            },
+        )
+        .join("\n\n");
+
+        assert!(
+            prompt.contains("Requester-Git-Email: will@relay.example.com <will@example.com>"),
+            "name part should fall back to nip05_handle when display_name is absent"
+        );
+    }
 }

crates/buzz-db/src/lib.rs

@@ -571,6 +571,7 @@ impl Db {
         avatar_url: Option<&str>,
         about: Option<&str>,
         nip05_handle: Option<&str>,
+        git_email: Option<&str>,
     ) -> Result<()> {
         user::update_user_profile(
             &self.pool,
@@ -579,6 +580,7 @@ impl Db {
             avatar_url,
             about,
             nip05_handle,
+            git_email,
         )
         .await
     }

crates/buzz-db/src/migration.rs

@@ -128,7 +128,7 @@ mod tests {
     fn embedded_migrator_contains_all_schema_migrations() {
         let migrations: Vec<_> = MIGRATOR.iter().collect();
 
-        assert_eq!(migrations.len(), 3);
+        assert_eq!(migrations.len(), 4);
         assert_eq!(migrations[0].version, 1);
         assert_eq!(&*migrations[0].description, "initial schema");
         assert!(
@@ -160,6 +160,16 @@ mod tests {
                 && migrations[2].sql.as_str().contains("idx_events_not_before"),
             "third migration should add the NIP-ER reminder columns and index"
         );
+
+        assert_eq!(migrations[3].version, 4);
+        assert_eq!(&*migrations[3].description, "user git email");
+        assert!(
+            migrations[3]
+                .sql
+                .as_str()
+                .contains("ADD COLUMN git_email TEXT"),
+            "fourth migration should add the git_email column to users"
+        );
     }
 
     async fn connect_test_pool() -> PgPool {