feat(schedule): add explicit-time-zone cron reminders

docs/tool-catalog.md

@@ -27,7 +27,7 @@ This table connects model-visible tool names to the plugin package and service s
 | `@deepseek-ai/dsh-tool-fs-search` | `glob`, `grep` | `ctx.tools`, `ctx.subprocess`, `ctx.systemPrompt` | `tool/call`, `tool/result` | - | glob and grep are unconditional discovery tools that spawn the packaged ripgrep binary (`@vscode/ripgrep`) through ctx.subprocess as ordinary foreground calls (never background tasks) — no host `rg` install and no shell layer. The catalog uses `sampleOverCapGlobResults: true`; deployments must choose that behavior explicitly. Capped results save the complete formatted list through the optional ctx.spillStore backend; returned locators are follow-up-readable/searchable when the backend exposes local paths in co-located deployments. |
 | `@deepseek-ai/dsh-tool-pty` | `terminal_close`, `terminal_list`, `terminal_open`, `terminal_read`, `terminal_send`, `terminal_signal` | `ctx.tools`, `ctx.pty`, `ctx.systemPrompt`, `ctx.tasks at call time for run_in_background` | `tool/call`, `tool/result` | - | The six terminal tools are opt-in and complement one-shot bash/filesystem tools. `terminal_send(run_in_background: true)` registers with `ctx.tasks`; TUI, named key sequences, BEL, resize, auto-start, and cross-agent sharing are absent from the schema. |
 | `@deepseek-ai/dsh-tool-goal` | `create_goal`, `get_goal`, `update_goal` | `ctx.tools`, `ctx.agents`, `ctx.goals`, `ctx.systemPrompt`, `a calling Agent in an authorized open turn` | `tool/call`, `goal/change for mutations`, `tool/result` | - | create, edit, pause, and resume require direct-human root authority; complete and blocked also accept the exact current goal round. The default blocked lower bound is three admitted rounds. |
-| `@deepseek-ai/dsh-tool-schedule` | `schedule_create`, `schedule_delete`, `schedule_list` | `ctx.tools`, `ctx.sessions`, `Session persistence`, `a future live root Agent` | `tool/call`, `schedule/change create or delete`, `tool/result` | - | Registered only inside live root Agent scopes created after the opt-in Schedule plugin loads. Version 1 accepts positive safe-integer after_seconds and discloses session-local delivery; management reads and mutations require the shared Session persistence barrier. |
+| `@deepseek-ai/dsh-tool-schedule` | `schedule_create`, `schedule_delete`, `schedule_list` | `ctx.tools`, `ctx.sessions`, `Session persistence`, `a future live root Agent` | `tool/call`, `schedule/change create or delete`, `tool/result` | - | Registered only inside live root Agent scopes created after the opt-in Schedule plugin loads. Version 1 accepts after_seconds, absolute at, fixed-rate every_seconds, and restricted five-field cron with an explicit IANA time_zone, and discloses session-local delivery; management reads and mutations require the shared Session persistence barrier. |
 | `@deepseek-ai/dsh-tool-lsp` | `lsp` | `ctx.tools`, `ctx.lsp`, `ctx.systemPrompt` | `tool/call`, `tool/result` | - | The lsp tool keeps provider selection and language-server subprocesses behind ctx.lsp, so its model-visible schema stays stable across providers. Requires a registered provider (e.g. `@deepseek-ai/dsh-lsp-local`) at runtime; without one, a query returns the structured `LSP_UNAVAILABLE` error rather than changing the schema. |
 | `@deepseek-ai/dsh-tool-ralph` | `ralph` | `ctx.tools`, `ctx.workflows`, `ctx.subagents`, `ctx.systemPrompt`, `a calling Agent (exec.agent parents every fresh round)` | `tool/call`, `tool/result`, `workflow and child session events during execution` | - | A fixed foreground workflow starts one fresh structured child per round; the model selects only the immutable objective and an optional round cap. |
 | `@deepseek-ai/dsh-tool-skill` | `skill` | `ctx.tools`, `ctx.agents`, `ctx.skills` | `tool/call`, `tool/result`, `user/message replacement catalogs via agent.inject()` | - | - |
@@ -831,7 +831,7 @@ create, edit, pause, and resume require direct-human root authority; complete an
 
 ### `schedule_create`
 
-Create one reminder in the current session. Supply a non-empty prompt and exactly one selector: a positive safe-integer after_seconds delay, at as a strict offset date-time or local date/time object, or safe-integer every_seconds of at least 300. Delivery is session-local: the reminder runs on time only while this session is live and otherwise becomes overdue until the session is resumed.
+Create one reminder in the current session. Supply a non-empty prompt and exactly one selector: a positive safe-integer after_seconds delay, at as a strict offset date-time or local date/time object, safe-integer every_seconds of at least 300, or a restricted five-field cron paired with an explicit IANA time_zone. Delivery is session-local: the reminder runs on time only while this session is live and otherwise becomes overdue until the session is resumed.
 
 ```json
 {
@@ -849,6 +849,14 @@ Create one reminder in the current session. Supply a non-empty prompt and exactl
       "type": "number",
       "description": "Fixed-rate safe-integer interval in seconds, at least 300."
     },
+    "cron": {
+      "type": "string",
+      "description": "Five numeric fields in order: minute 0-59, hour 0-23, day-of-month 1-31, month 1-12, day-of-week 0-7 (0 and 7 are Sunday). Each field is *, one integer, a strictly increasing integer list, an increasing a-b range, */s, or a-b/s. Day-of-month or day-of-week must be *. Steps are positive and at most the field cardinality (7 for day-of-week). Names, macros, seconds, years, ?, L, W, and # are unsupported; nominal matches must be at least five minutes apart. Requires time_zone."
+    },
+    "time_zone": {
+      "type": "string",
+      "description": "Explicit UTC or IANA Area/Location for cron evaluation."
+    },
     "at": {
       "oneOf": [
         {
@@ -920,7 +928,7 @@ List every active reminder in the current session in creation order, including i
 
 Source: [`packages/schedule/tool-schedule/src/tools.ts`](../packages/schedule/tool-schedule/src/tools.ts)
 
-Registered only inside live root Agent scopes created after the opt-in Schedule plugin loads. Version 1 accepts positive safe-integer after_seconds and discloses session-local delivery; management reads and mutations require the shared Session persistence barrier.
+Registered only inside live root Agent scopes created after the opt-in Schedule plugin loads. Version 1 accepts after_seconds, absolute at, fixed-rate every_seconds, and restricted five-field cron with an explicit IANA time_zone, and discloses session-local delivery; management reads and mutations require the shared Session persistence barrier.
 
 ## `@deepseek-ai/dsh-tool-lsp`