fix: split WriteAgentStateFile into WriteAgentForgeToken + WriteAgentMatrixToken

Addresses mara's review: each credential type gets its own PrivRequest
variant, making the exact priv surface visible in the wire protocol.
No runtime filename dispatch — the operation name is the gate.

- WriteAgentForgeToken { agent_name, token } → state/forge-token
- WriteAgentMatrixToken { agent_name, token } → state/matrix-token
- priv_client: two typed fns (write_agent_forge_token, write_agent_matrix_token)
- forge.rs: split mint_and_persist_token into mint_and_persist_agent_token
  (priv) + mint_and_persist_core_token (direct write); drop dead token_path fn
- matrix.rs: call write_agent_matrix_token directly

hive-c0re/src/forge.rs

@@ -74,12 +74,6 @@ const TOKEN_SCOPES: &str = "read:user,write:user,read:notification,write:notific
 /// See `docs/forge.md::Token scopes`.
 const CORE_TOKEN_SCOPES: &str = "read:admin,write:admin,read:user,write:user,read:notification,write:notification,write:repository,write:issue,write:organization,write:misc";
 
-/// Token file inside the agent's bind-mounted state dir (visible as
-/// `/state/forge-token` from inside the container).
-fn token_path(name: &str) -> PathBuf {
-    Coordinator::agent_notes_dir(name).join("forge-token")
-}
-
 /// Probe whether `hive-forge` exists as a nixos-container. Cheap —
 /// `nixos-container list` is just a directory scan in /etc. Routed
 /// through hive-priv: `nixos-container` needs root, and hive-c0re runs
@@ -291,41 +285,30 @@ async fn mint_token(name: &str, scopes: &str) -> Result<String> {
     Ok(token)
 }
 
-/// Mint a fresh access token for `name` and persist it to `path` (0600).
+/// Mint a fresh Forgejo access token for an agent and write it to the
-/// For paths outside the agent state tree (e.g. the core admin token at
+/// agent's state dir via hive-priv. hive-c0re runs unprivileged and
-/// `/var/lib/hyperhive/forge-core-token`), writes directly — hive-c0re
+/// cannot write to agent-owned (0755) state directories directly.
-/// owns those paths. For paths inside `AGENT_STATE_ROOT` the write is
+async fn mint_and_persist_agent_token(name: &str) -> Result<()> {
-/// routed through hive-priv (root helper) because hive-c0re runs
+    let token = mint_token(name, TOKEN_SCOPES).await?;
-/// unprivileged and cannot write to agent-owned state directories.
+    crate::priv_client::write_agent_forge_token(name, &token)
-async fn mint_and_persist_token(name: &str, path: &Path, scopes: &str) -> Result<()> {
+        .await
+        .with_context(|| format!("write forge-token for {name} via hive-priv"))
+}
+
+/// Mint a fresh Forgejo access token for the `core` admin user and
+/// write it directly to `path`. Unlike agent tokens this path is owned
+/// by hive-c0re itself (under `/var/lib/hyperhive/`), so a direct
+/// write is both correct and necessary (no priv round-trip).
+async fn mint_and_persist_core_token(path: &Path) -> Result<()> {
     use std::os::unix::fs::PermissionsExt;
-    let token = mint_token(name, scopes).await?;
+    let token = mint_token("core", CORE_TOKEN_SCOPES).await?;
-
-    // Agent state paths must go through hive-priv.
-    // Heuristic: any path containing an "agents" component is considered
-    // an agent state path (matches `/var/lib/hyperhive/agents/<name>/...`).
-    // All current callers pass either CORE_TOKEN_PATH (no "agents" component)
-    // or `token_path(name)` (under AGENT_STATE_ROOT which contains "agents").
-    // If a future non-agent path ever gains an "agents" component, this guard
-    // would incorrectly route it to priv — add an explicit exclusion then.
-    if path.components().any(|c| c.as_os_str() == "agents") {
-        let filename = path
-            .file_name()
-            .and_then(|n| n.to_str())
-            .context("could not determine filename for priv write")?;
-        return crate::priv_client::write_agent_state_file(name, filename, &format!("{token}\n"))
-            .await
-            .with_context(|| format!("write {filename} for {name} via hive-priv"));
-    }
-
-    // Non-agent paths (core admin token, etc.): write directly.
     if let Some(parent) = path.parent() {
         std::fs::create_dir_all(parent).ok();
     }
     std::fs::write(path, format!("{token}\n"))
-        .with_context(|| format!("write token to {}", path.display()))?;
+        .with_context(|| format!("write core token to {}", path.display()))?;
     let _ = std::fs::set_permissions(path, std::fs::Permissions::from_mode(0o600));
-    tracing::info!(%name, path = %path.display(), "forge: persisted access token");
+    tracing::info!(path = %path.display(), "forge: persisted core access token");
     Ok(())
 }
 
@@ -338,7 +321,7 @@ pub async fn ensure_user_for(name: &str) -> Result<()> {
     }
     ensure_user_exists(name, false, None).await?;
     ensure_user_email(name).await;
-    mint_and_persist_token(name, &token_path(name), TOKEN_SCOPES).await
+    mint_and_persist_agent_token(name).await
 }
 
 /// Provision a forgejo user for `name` and return the freshly-minted
@@ -451,7 +434,7 @@ async fn ensure_core_user_and_token() -> Result<String> {
         }
     }
     ensure_user_exists("core", true, None).await?;
-    mint_and_persist_token("core", path, CORE_TOKEN_SCOPES).await?;
+    mint_and_persist_core_token(path).await?;
     let raw = std::fs::read_to_string(path)
         .with_context(|| format!("read {CORE_TOKEN_PATH} after mint"))?;
     Ok(raw.trim().to_owned())

hive-c0re/src/matrix.rs

@@ -420,7 +420,7 @@ pub async fn ensure_user_for(
     // unprivileged `hive-core` user and cannot write to agent-owned state
     // directories directly. hive-priv writes the file 0600 and chowns it
     // to the agent user so it is readable from inside the container.
-    crate::priv_client::write_agent_state_file(name, "matrix-token", &format!("{access_token}\n"))
+    crate::priv_client::write_agent_matrix_token(name, &access_token)
         .await
         .with_context(|| format!("matrix: write matrix-token for {name} via hive-priv"))?;
     tracing::info!(%name, "matrix: provisioned access token");

hive-c0re/src/priv_client.rs

@@ -256,18 +256,26 @@ pub async fn run_forge_admin(args: &[&str]) -> Result<(String, String)> {
     check(call(&PrivRequest::RunForgeAdmin { args: owned }).await?)
 }
 
-/// Write `content` to `<agent_state_root>/<agent_name>/state/<filename>`
+/// Write the Forgejo access token for `agent_name` to
-/// via hive-priv (running as root). The file is written 0600 and chowned
+/// `<agent_state_root>/<agent_name>/state/forge-token` via hive-priv
-/// to the agent user so it is readable from inside the agent container.
+/// (running as root). The file is written 0600 and chowned to the agent
-///
+/// user so it is readable from inside the agent container.
-/// Used for credential files (forge-token, matrix-token) that hive-c0re
+pub async fn write_agent_forge_token(agent_name: &str, token: &str) -> Result<()> {
-/// mints but cannot write directly because those paths are inside agent-
+    ok(call(&PrivRequest::WriteAgentForgeToken {
-/// owned (0755) state directories and hive-c0re runs unprivileged.
-pub async fn write_agent_state_file(agent_name: &str, filename: &str, content: &str) -> Result<()> {
-    ok(call(&PrivRequest::WriteAgentStateFile {
         agent_name: agent_name.to_owned(),
-        filename: filename.to_owned(),
+        token: token.to_owned(),
-        content: content.to_owned(),
+    })
+    .await?)
+}
+
+/// Write the Matrix access token for `agent_name` to
+/// `<agent_state_root>/<agent_name>/state/matrix-token` via hive-priv
+/// (running as root). The file is written 0600 and chowned to the agent
+/// user so it is readable from inside the agent container.
+pub async fn write_agent_matrix_token(agent_name: &str, token: &str) -> Result<()> {
+    ok(call(&PrivRequest::WriteAgentMatrixToken {
+        agent_name: agent_name.to_owned(),
+        token: token.to_owned(),
     })
     .await?)
 }

hive-priv/src/main.rs

@@ -322,38 +322,28 @@ async fn exec(req: PrivRequest, writer: &mut OwnedWriteHalf) -> Result<(String,
             run_forge_admin(args).await
         }
 
-        PrivRequest::WriteAgentStateFile {
+        PrivRequest::WriteAgentForgeToken {
             ref agent_name,
-            ref filename,
+            ref token,
-            ref content,
         } => {
             validate_agent_name(agent_name)?;
-            validate_state_filename(filename)?;
+            write_agent_state_file(agent_name, "forge-token", &format!("{token}\n"))
-            write_agent_state_file(agent_name, filename, content)
+        }
+
+        PrivRequest::WriteAgentMatrixToken {
+            ref agent_name,
+            ref token,
+        } => {
+            validate_agent_name(agent_name)?;
+            write_agent_state_file(agent_name, "matrix-token", &format!("{token}\n"))
         }
     }
 }
 
-/// Explicit allowlist of filenames `WriteAgentStateFile` may write.
+/// Shared helper for `WriteAgentForgeToken` and `WriteAgentMatrixToken`.
-/// New credential files must be added here deliberately — hive-priv
+/// Writes `content` to `AGENT_STATE_ROOT/<agent_name>/state/<filename>`,
-/// rejects any filename not in this list.
+/// chowns to the agent user (derived from the state dir's existing owner),
-const ALLOWED_STATE_FILENAMES: &[&str] = &["forge-token", "matrix-token"];
+/// and chmods 0600. Running as root (hive-priv), so this succeeds
-
-/// Validate a filename destined for `WriteAgentStateFile` against the
-/// explicit allowlist. Only known credential filenames are accepted.
-fn validate_state_filename(filename: &str) -> Result<()> {
-    if !ALLOWED_STATE_FILENAMES.contains(&filename) {
-        bail!(
-            "state filename {filename:?} not in allowlist {:?}",
-            ALLOWED_STATE_FILENAMES
-        );
-    }
-    Ok(())
-}
-
-/// Write `content` to `AGENT_STATE_ROOT/<agent_name>/state/<filename>`,
-/// chown to the agent user (derived from the state dir's existing owner),
-/// and chmod 0600. Running as root (hive-priv), so all of this succeeds
 /// regardless of the file's prior owner/permissions.
 fn write_agent_state_file(
     agent_name: &str,

hive-sh4re/src/priv_proto.rs

@@ -229,29 +229,29 @@ pub enum PrivRequest {
         args: Vec<String>,
     },
 
-    // --- Agent state file writes ---
+    // --- Agent credential writes ---
-    /// Write a credential file into an agent's bind-mounted state directory.
+    /// Write `forge-token` into `AGENT_STATE_ROOT/<agent_name>/state/forge-token`.
     ///
-    /// Path resolved by hive-priv: `AGENT_STATE_ROOT/<agent_name>/state/<filename>`.
+    /// hive-priv validates `agent_name`, creates the state dir if absent,
-    /// hive-priv validates both the agent name and filename before writing.
+    /// writes the file 0600, and chowns it to the state dir's owner so
-    ///
+    /// the agent process can read it. Required because hive-c0re runs
-    /// After writing, the file is chowned to the agent user's uid/gid
+    /// unprivileged and cannot write to agent-owned state directories.
-    /// (read from the state directory's owner) and chmoded 0600 so
+    WriteAgentForgeToken {
-    /// only the agent process can read it.
-    ///
-    /// Required because hive-c0re runs as the unprivileged `hive-core`
-    /// user and cannot write to agent-owned (0755) state directories
-    /// after the privsep that moved c0re from root to a dedicated unix user.
-    WriteAgentStateFile {
         /// Logical agent name (validated by `validate_agent_name`).
         agent_name: String,
-        /// Allowlisted credential filename within the state dir.
+        /// Token value. hive-priv appends a trailing newline before writing.
-        /// Only `"forge-token"` and `"matrix-token"` are accepted;
+        token: String,
-        /// hive-priv rejects any other value.
+    },
-        filename: String,
+
-        /// File content to write. Written as-is; caller is responsible for
+    /// Write `matrix-token` into `AGENT_STATE_ROOT/<agent_name>/state/matrix-token`.
-        /// including any trailing newline.
+    ///
-        content: String,
+    /// Same semantics as `WriteAgentForgeToken` — validates name, creates
+    /// dir, writes 0600, chowns to agent owner.
+    WriteAgentMatrixToken {
+        /// Logical agent name (validated by `validate_agent_name`).
+        agent_name: String,
+        /// Token value. hive-priv appends a trailing newline before writing.
+        token: String,
     },
 }