heph.nvim: task views — next/list/capture/attention/state/log (slice 11b)

Backend: enrich `list` to return titled RankedTask rows (title +
canonical_context_id, via a shared ranked_from_row with `next`), so the
Organizational view needs no N+1 node.get. TDD: query_surface test asserts
list rows carry title + context id.

Plugin:
- view.lua: Tactical `next` + Organizational `list` rendered scratch buffers;
  <CR> opens the row's canonical-context doc. Narrowed the node autocmd to
  heph://node/* so view buffers (heph://next, heph://list) don't trip it.
- task.lua: capture, set-attention, done/drop, skip, per-task log append, all
  resolving "the current task" from the buffer (a task node, or a context doc
  via its canonical-context backlink).
- picker.lua: vim.ui.select with Telescope auto-upgrade (headless-safe).
- command.lua: :Heph next/list/capture/attention/done/drop/skip/log/search.

e2e: capture→next→open context→add/check checklist→done; recurring
fresh-checklist (complete rolls forward in place, next occurrence all-unchecked
— the §4.4 hard requirement). 6 specs green via `mise run test-nvim`.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

heph.nvim/lua/heph/view.lua

@@ -0,0 +1,89 @@
+--- Task list views (tech-spec §8): Tactical `next` (the "what is next?" ranking)
+--- and Organizational `list` (the whole outstanding set). Both render the same
+--- titled rows the daemon returns into a scratch buffer; `<CR>` opens the task
+--- under the cursor's canonical-context doc (the one-keystroke jump).
+
+local rpc = require("heph.rpc")
+
+local M = {}
+
+-- buf -> { tasks = <RankedTask[]> }; line N maps to tasks[N].
+M._views = {}
+
+local function row(t)
+  local tag = t.attention and ("[" .. t.attention .. "]") or "[ ]"
+  return string.format("%s %s", tag, t.title)
+end
+
+-- Find or create the named scratch buffer and fill it with task rows.
+local function render(name, tasks)
+  local buf
+  for _, b in ipairs(vim.api.nvim_list_bufs()) do
+    if vim.api.nvim_buf_get_name(b) == name then
+      buf = b
+      break
+    end
+  end
+  if not buf then
+    buf = vim.api.nvim_create_buf(false, true) -- unlisted scratch
+    vim.api.nvim_buf_set_name(buf, name)
+  end
+  vim.bo[buf].buftype = "nofile"
+  vim.bo[buf].bufhidden = "hide"
+  vim.bo[buf].swapfile = false
+
+  local lines = {}
+  for _, t in ipairs(tasks) do
+    lines[#lines + 1] = row(t)
+  end
+  if #lines == 0 then
+    lines = { "(nothing here)" }
+  end
+  vim.bo[buf].modifiable = true
+  vim.api.nvim_buf_set_lines(buf, 0, -1, false, lines)
+  vim.bo[buf].modifiable = false
+
+  M._views[buf] = { tasks = tasks }
+  vim.keymap.set("n", "<CR>", function()
+    M.open_under_cursor(buf)
+  end, { buffer = buf, desc = "heph: open task context" })
+  vim.api.nvim_set_current_buf(buf)
+  return buf
+end
+
+--- Open the canonical-context doc of the task on the cursor line.
+function M.open_under_cursor(buf)
+  buf = buf or vim.api.nvim_get_current_buf()
+  local view = M._views[buf]
+  if not view then
+    return
+  end
+  local lnum = vim.api.nvim_win_get_cursor(0)[1]
+  local t = view.tasks[lnum]
+  if not t then
+    return
+  end
+  require("heph.node").open(t.canonical_context_id or t.node_id)
+end
+
+--- Tactical "what is next?" — render the ranking, return the rows.
+function M.next(opts)
+  opts = opts or {}
+  local tasks = rpc.call("next", { scope = opts.scope, limit = opts.limit or 5 })
+  render("heph://next", tasks)
+  return tasks
+end
+
+--- Organizational survey — render the outstanding set, return the rows.
+function M.list(opts)
+  opts = opts or {}
+  local tasks = rpc.call("list", {
+    scope = opts.scope,
+    attention = opts.attention,
+    include_blue = opts.include_blue ~= false,
+  })
+  render("heph://list", tasks)
+  return tasks
+end
+
+return M