…e file visibility

Fixes #2495.

When `user_prompt` opens an elicitation pop-up with many enum items
(or many fields, or a long message) the dialog overflowed the bottom
of the terminal with no way to access the clipped content — neither
visually nor for keyboard navigation.

The body region (message + fields, or message + free-form input) is
now rendered inside a scrollview, capped at 80% of the terminal
height (max 40 rows). Title/separator stay fixed at the top, the help
line stays fixed at the bottom.

- The scrollview consumes mouse wheel, scrollbar drag, and
  PgUp/PgDn/Home/End. Up/Down keep their existing role of cycling
  enum/boolean selections.
- Auto-scroll keeps the focused field's active line visible: Tab /
  Shift-Tab brings the new field into view, and Up/Down inside an
  enum/boolean keeps the selected option in view even when the field
  itself is taller than the viewport. Submit-with-error focuses and
  scrolls to the offending field.
- Mouse clicks translate the absolute Y through the current scroll
  offset before mapping to a field/option, so clicks on visible
  options still work when the dialog is scrolled.
- The help line gains a "pgup/pgdn scroll" hint when scrolling is
  active.
- A single layout() method computes geometry (dialog width, viewport,
  body lines, per-field line offsets) shared by View() and
  Position(), so layout math lives in exactly one place.
- buildBody tracks line offsets incrementally to stay O(N) in the
  number of fields.

Tests cover long enums (30 options on a 20-row terminal), many
fields below the fold (15 fields on an 18-row terminal), and small
content that should not show a scrollbar.

Assisted-By: docker-agent

Automated changelog update for release v1.51.0

Assisted-By: Docker Agent

docs: update CHANGELOG.md for v1.51.0

…ssue-2495-35d25358

fix(tui): make user_prompt elicitation dialog scrollable

…n-ignored

hotkeys to toggle filepicker hidden/ignored files

Ensure strings.TrimSpace() is used only as a skip guard, never to mutate
the content that reaches the provider API. Fixes inconsistencies across
Anthropic, OpenAI, Bedrock, Gemini, and oaistream-based providers.

Changes:
- Anthropic (standard + Beta): single-part user messages, multi-part text
  parts, and tool-result content now send the original untrimmed value.
  Tool-result blocks are normalized to empty string (not skipped) when
  whitespace-only, because every tool_use must have a corresponding
  tool_result.
- OpenAI oaistream / Chat Completions: ConvertMultiContent switched from
  pre-allocated slice to append-based; adds TrimSpace guard on text parts
  so whitespace-only and empty parts are not forwarded. Same guard added
  to tool-role multi-content text parts.
- OpenAI Responses API: adds TrimSpace guard on multi-part user message
  text parts in convertMessagesToResponseInput.
- Gemini: strengthens single-part guard from != "" to TrimSpace != "";
  adds TrimSpace guard in convertMultiContent for multi-part text parts.
- Test: updates the oaistream ConvertMultiContent test to assert the
  corrected behavior (nil-URL image part produces no output part, not a
  zero-value entry); adds whitespace-only text part test case.

Fixes #2515

Assisted-By: docker-agent

Assisted-By: docker-agent

…opic API

The previous Anthropic provider code trimmed trailing whitespace before
sending content to the API. Now that the original untrimmed content is sent,
cassettes need to reflect the actual bodies:

- TestDebug_Title/Anthropic*: sessiontitle generator builds prompts with
  fmt.Fprintf('%d. %s\n', ...) + a trailing '\n\n' in the format string,
  producing three trailing newlines. The old TrimSpace stripped these; the
  new code sends them as-is.

- TestExec_Anthropic_ToolCall: list_directory tool output ends with '\n'
  (from fmt.Fprintf 'FILE %s\n'). The old TrimSpace on tool results stripped
  this; the new code sends the original content.

Assisted-By: docker-agent

When multiple steer messages are drained in one batch they were injected
back-to-back with no separator, causing some chat templates that
concatenate consecutive user messages before tokenisation to glue
adjacent word fragments together.

Fix: introduce drainAndEmitSteered() which appends "\n" to every
non-last message's content before calling appendSteerAndEmit.
For multi-content messages the "\n" is appended to the last text part
(or a new text part is added when none exists). The original
QueuedMessage slice is never mutated — appendNewlineToQueuedMessage
works on a shallow copy.

The three inline steerQueue.Drain() + for-loop sites in loop.go are
replaced by calls to the new helper.

Tests added:
- TestAppendNewlineToQueuedMessage: unit-tests the pure helper across
  plain-text, multi-content-with-text-part, multi-content-no-text-part,
  and no-mutation cases.
- TestDrainAndEmitSteered_MultipleMessages: verifies three plain-text
  messages are kept as separate session messages with \n on non-last ones.
- TestDrainAndEmitSteered_MultiContent: verifies the same for
  multi-content messages.

Fixes #2517

Assisted-By: docker-agent

Replace make([]T, len)+copy with append(nil, src...) to avoid appending
to a non-zero-initialized slice, which triggers the makezero linter.

Assisted-By: docker-agent

Reshape pkg/hooks from "7 hard-coded events with bespoke per-event
boilerplate" into a generic Dispatch/Has surface backed by a pluggable
Registry. Add 5 new lifecycle events and 3 in-process builtin hooks
that extract previously-inline runtime concerns. Strictly additive at
the YAML layer: every existing hooks YAML keeps parsing untouched.

Architecture:

- Handler/Registry seam: Executor resolves each Hook's HookType
  against a Registry of HandlerFactory values. The default registry
  ships HookTypeCommand (the long-standing shell-out behavior, lifted
  into a Handler) and HookTypeBuiltin (a new handler kind that
  dispatches by name to an in-process Go function). Adding a new
  handler kind is one Register call; extending Hook with `args: []`
  lets builtins receive per-hook parameters.
- Dispatch/Has API: collapse 7 ExecuteXxx + 7 HasXxxHooks methods
  into Dispatch(ctx, event, input) and Has(event), backed by an
  eventTable built once at construction. Adding a new event becomes
  a one-line entry; the executor needs no per-event methods or fields.
- Builtin lookup is per-Registry, not global: NewLocalRuntime builds
  a private hooks.Registry, registers the three runtime-owned
  builtins on it, and threads it into every executor. No init()
  functions, no shared mutable state, no cross-runtime pollution.

New events (5):

  turn_start         fires per model call, AFTER the persisted
                     messages are read. AdditionalContext is appended
                     transiently and never persisted, so per-turn
                     signals refresh every turn.
  before_llm_call    just before each model invocation. Observational.
  after_llm_call     just after a successful model call. Carries the
                     assistant text via stop_response.
  on_error           structured handler for runtime errors (model
                     failures, tool-call loops). Fires alongside the
                     generic notification event.
  on_max_iterations  structured handler for hitting max_iterations.
                     Fires alongside the generic notification event.

Extracted runtime concerns (3 builtins):

  add_date              turn_start, "Today's date: YYYY-MM-DD"
  add_environment_info  session_start, working dir / OS / arch / git
  add_prompt_files      turn_start, reads files via Hook.Args

The runtime auto-injects them based on the existing AddDate /
AddEnvironmentInfo / AddPromptFiles agent flags, so YAMLs with those
flags keep working with identical effective behavior. Users can also
write the builtins explicitly in YAML now that the schema exposes
type=builtin.

Schema additions in pkg/config/latest:

- HooksConfig gains turn_start, before_llm_call, after_llm_call,
  on_error, on_max_iterations top-level keys.
- HookDefinition gains args: [string], used by builtin handlers to
  receive per-hook parameters.
- HookDefinition.type accepts "builtin" alongside "command".
- agent-schema.json updated to match.

User-facing surface:

- examples/hooks.yaml is a single canonical example covering all
  twelve events and both handler kinds (replaces five separate
  hooks_*.yaml files).
- The legacy ExecuteXxx / HasXxxHooks shims on Executor are gone;
  every caller migrated to Dispatch / Has.

Bug fixes uncovered along the way:

- Default LocalRuntime.workingDir to os.Getwd() when no caller passed
  WithWorkingDir, matching the session's default. Fixes
  add_prompt_files reading an empty Cwd in CLI invocations.
- Restore cache_control marker on the last extra in
  Session.GetMessages so AddPromptFiles content keeps participating
  in Anthropic prompt caching.
- Route plain stdout from turn_start command hooks into
  AdditionalContext (was silently dropped, while session_start did
  surface it).
- Extend hook deduplication from (type, command) to (type, command,
  args) so two add_prompt_files hooks with different file lists fire
  as distinct invocations.
- Fix MergeHooks to also merge Stop, Notification, and the new event
  slices (previously dropped Stop / Notification when both base and
  CLI were non-empty).
- Align hook helpers' log levels to Warn
  (executeSessionEndHooks was the odd Error out).

Validated with go vet ./..., golangci-lint run ./... (0 issues), and
go test -race across pkg/hooks, pkg/runtime, pkg/session, pkg/config
(all versions), and e2e.

Assisted-By: docker-agent

S1: add NOTE comment in drainAndEmitSteered documenting that the
    appended \n is persisted in session messages and UserMessageEvent.
S2: appendNewlineToQueuedMessage now returns sm unchanged when
    MultiContent has no text part (e.g. image-only) instead of
    appending a synthetic whitespace text part. Non-text parts carry
    their own envelope that acts as a separator, and pure whitespace
    parts are skipped downstream anyway.
S3: drainAndEmitSteered now returns (bool, int) where int is the
    pre-drain message count; callers no longer need a separate
    len(sess.GetAllMessages()) call before draining.
N3: add plain-text no-mutation subtest in TestAppendNewlineToQueuedMessage.
N4: reword appendNewlineToQueuedMessage doc comment.

Assisted-By: docker-agent

…Messages

Addresses reviewer feedback: 'Is it possible to normalise the behaviour in only
one place? In the place where we make the slice of messages of the session?'

Add normalizeMessageContent() to session.GetMessages as the single, authoritative
place where whitespace-only content is pruned before any provider converter sees
it. This replaces the patchwork of per-provider TrimSpace skip-guards.

Rules applied by normalizeMessageContent:
- Tool-result messages (Role=tool) are always forwarded, even when empty, because
  every tool_use block must have a corresponding tool_result.
- Assistant messages with ToolCalls or FunctionCall are always forwarded even when
  Content is empty — the content field is optional when tool calls are present.
- Any other message whose Content is whitespace-only (and has no MultiContent) is
  dropped.
- Within MultiContent, text parts whose Text is whitespace-only are stripped;
  non-text parts (images, files) are preserved as-is. If all parts are stripped the
  whole message is dropped.

Provider-converter changes:
- All per-converter TrimSpace skip-guards for user/assistant/system messages
  removed (they are now redundant): Anthropic std+Beta convertMessages,
  oaistream ConvertMultiContent + tool-role multi-content, OpenAI Responses API
  user multi-content, Gemini convertMessagesToGemini + convertMultiContent.
- Pre-existing assistant empty-skip guards in oaistream and openai/client.go are
  kept: they handle streaming artifacts (max_tokens assistant deltas) that are
  produced outside of GetMessages and may not pass through normalizeMessageContent.
- Anthropic system blocks (extractSystemBlocks / extractBetaSystemBlocks) continue
  to TrimSpace because YAML literal-block instructions (instruction: |) always
  append a trailing newline, and the system-block builder is the right place to
  normalise that for the Anthropic API payload.
- The Anthropic send-original correctness fix (tool_result and conversation-message
  content: send original string, not trimmed value) is unchanged.

Tests updated throughout to document the new 'converter passes through, session
layer filters' contract.

Assisted-By: docker-agent

Instead of iterating to find the last text part, only inspect
sm.MultiContent[last]: if it is a text part, append \n; otherwise
return sm unchanged. Non-text parts carry their own provider envelope
that acts as a separator, so no \n is needed regardless of what
precedes them.

Update tests to match: replace the 3-part (text/image/text) subtest
with explicit last-part-text and last-part-non-text cases.

Assisted-By: docker-agent

…atter

Assisted-By: docker-agent

…wline-separator

runtime: append newline to non-last steer messages on multi-drain

…ng-consistency

fix: normalize message trimming behavior across all model providers

…r-extensibility-76cf250c

feat(hooks): refactor for extensibility, add 5 events and 3 builtins