Two small follow-on batches after #445:

1. hooks.formatHookOutcomeMessage — was hardcoded
   \`hook \${tag} \\`\${cmd}\\` \${decision}\${truncTag}\`. Pulls
   the structural words (\"hook\", decision verb, \" (output truncated
   at 256KB)\") into a new \`hooks.*\` namespace. The technical bits
   (tag, cmd) stay verbatim — they're identifiers, not prose.

2. loop/force-summary.ts — three user-visible strings:
   - \"summarizing what was gathered…\" (status during summary call)
   - the fallback when the model emits hallucinated tool-call markup
     instead of prose
   - the error template when the fallback summary itself crashes

New \`summary.*\` namespace covers all three. zh-CN translations included.

Decision verbs (block / warn / timeout / error) are translated via a
small \`hooks.decision\${Capitalize}\` lookup so the formatter still
takes \`outcome.decision\` (the typed enum) as input.

Test plan: full suite 2301 pass; tsc + biome clean.

Two patterns rolled into one PR:

1. Wire seven existing ui.* keys that had been defined in EN.ts /
   zh-CN.ts but never actually called: ephemeralSession,
   resumedSession, newSession, restoredEdits, resumedPlan,
   tipEditBindings, dashboardAutoStartFailed. The keys had drifted
   into dead code — same pattern that bit the loop.* namespace
   before #445.

2. New app.* namespace (~24 keys) covering every other hardcoded
   user-facing string in App.tsx:
   - walk cancel (with / without remaining count)
   - edit-mode cycle (review / auto / yolo)
   - reject / auto-approve / flip-to-auto messages
   - dashboard stopped, /restore code-mode-only
   - hash-memory note (with translated scope + verb)
   - bash-mode + memory-write failures
   - hook headers (UserPromptSubmit, Stop)
   - @mentions / @url expansion + failure
   - shell confirm (deny / always-allow / running / starting)
   - checkpoint saved
   - plan continue / stop / revise

zh-CN translations for all 31 new keys.

Test plan: full suite 2301 pass, tsc + biome clean.

Yields like 'session budget exhausted', 'aborted at iter X/Y',
'preflight: request ~X/Y tokens', and the post-turn fold/forcing-
summary status lines were all hardcoded English. The loop.* i18n
namespace had 7 keys defined but never wired — placeholders from a
previous attempt that drifted away from the actual call sites.

This PR replaces the dead namespace with 20 keys that match the
actual yield shapes, wires t() at every site, and adds zh-CN
translations.

Categories covered:
  - budget (exhausted / 80% warning)
  - /pro armed
  - aborted-at-iter / tool-budget-warning
  - preflight (status + folded / no-fold-left)
  - escalation (flash → pro / auto-escalation)
  - storm-broken (stuck retry loop / suppressed-N-times)
  - history compaction (status + folded / aggressively-folded)
  - forcing summary (context-guard exit)

Behavior preserved: tests pin runtime to EN, so existing assertions
on the English text still pass. The dead loop.* keys (budgetWarning,
budgetRefusal, contextWarning, escalationWarning, toolFailure,
interrupted, loopStopped) had zero callers across src/ and tests/
and are removed as part of the namespace cleanup.

…engine#446)

Two small follow-on batches after esengine#445:

1. hooks.formatHookOutcomeMessage — was hardcoded
   \`hook \${tag} \\`\${cmd}\\` \${decision}\${truncTag}\`. Pulls
   the structural words (\"hook\", decision verb, \" (output truncated
   at 256KB)\") into a new \`hooks.*\` namespace. The technical bits
   (tag, cmd) stay verbatim — they're identifiers, not prose.

2. loop/force-summary.ts — three user-visible strings:
   - \"summarizing what was gathered…\" (status during summary call)
   - the fallback when the model emits hallucinated tool-call markup
     instead of prose
   - the error template when the fallback summary itself crashes

New \`summary.*\` namespace covers all three. zh-CN translations included.

Decision verbs (block / warn / timeout / error) are translated via a
small \`hooks.decision\${Capitalize}\` lookup so the formatter still
takes \`outcome.decision\` (the typed enum) as input.

Test plan: full suite 2301 pass; tsc + biome clean.

Two patterns rolled into one PR:

1. Wire seven existing ui.* keys that had been defined in EN.ts /
   zh-CN.ts but never actually called: ephemeralSession,
   resumedSession, newSession, restoredEdits, resumedPlan,
   tipEditBindings, dashboardAutoStartFailed. The keys had drifted
   into dead code — same pattern that bit the loop.* namespace
   before esengine#445.

2. New app.* namespace (~24 keys) covering every other hardcoded
   user-facing string in App.tsx:
   - walk cancel (with / without remaining count)
   - edit-mode cycle (review / auto / yolo)
   - reject / auto-approve / flip-to-auto messages
   - dashboard stopped, /restore code-mode-only
   - hash-memory note (with translated scope + verb)
   - bash-mode + memory-write failures
   - hook headers (UserPromptSubmit, Stop)
   - @mentions / @url expansion + failure
   - shell confirm (deny / always-allow / running / starting)
   - checkpoint saved
   - plan continue / stop / revise

zh-CN translations for all 31 new keys.

Test plan: full suite 2301 pass, tsc + biome clean.