feat(hook-augment): augment Bash tool searches via graph

[abendrothj]

Fixes #1082.

What

Claude Code frequently runs searches through the Bash tool (rg -n Foo ., grep -rn Foo ., etc.) rather than the native Grep/Glob tools. Because hook-augment's PreToolUse matcher only covered Grep and Glob, these searches silently bypassed graph augmentation.

This PR adds detection directly in hook_augment itself (Q1 from my earlier comment — I went with the former approach since it reuses the existing search_graph path without duplicating resolver logic). Pattern extraction happens via a small shell tokenizer and flag parser; the result feeds into the same ha_extract_token → search_graph path Grep already uses.

Approach

ha_tokenize — minimal shell tokenizer: whitespace split with '…'/"…" quoting and backslash handling. No evaluation, no expansion.

ha_parse_bash_search_pattern — pure string parser, never touches the command:

• Strips leading VAR=value env assignments
• Strips wrappers: env, nice, time, command, rtk, tokf run
• Identifies the binary (grep/egrep/fgrep, rg, ag, ack, ugrep/ug, git grep)
• Walks flags: bails on -f/--file (pattern file), bails on multiple -e, handles embedded (-ePATTERN) and space-separated (-e PATTERN) forms
• Per-binary value-taking flag tables so e.g. grep -A 5 PATTERN correctly skips 5
• rtk grep -l <N>: treats -l as value-taking (consumes N, arrives at PATTERN)

ha_tool_event_supported — Bash added alongside Grep/Glob for PreToolUse in HA_DIALECT_EVENT.

ha_process — Bash branch extracts pattern from tool_input.command; everything after is identical to the Grep path.

Scope (Q2)

grep/egrep/fgrep, rg, ag, ack, ugrep/ug, git grep — plus the wrapper handling dergachoff noted in the thread.

Testing

cli_hook_augment_bash_pattern_extractor in tests/test_cli.c covers: common invocation forms, value-taking flag skipping, env-var prefixes, all wrappers, the rtk grep -l <N> case, bail-out cases (-f, multiple -e, non-search binary, empty/NULL), and -- end-of-flags. Verified clean compile and production binary build on macOS; full test run blocked by an ASan/dyld hang on macOS 26 pre-release — CI should cover it.

[abendrothj]

The cppcheck failure is pre-existing in src/main.c lines 283 and 2049; introduced by a recent merge to main, not by this PR.